Riak example cluster configuration with 3 nodes (riak1, riak2 and riak3)

riak1.app.config

%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.10", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.10", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.10", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Riak CS paths
            {add_paths, ["/usr/lib/riak-cs/lib/riak_cs-1.4.0/ebin"]},

            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% Riak CS Configuration...
            {multi_backend_prefix_list, [{<<"0b:">>, be_blocks}]},
            {multi_backend_default, be_default},
            {multi_backend, [
              {be_default, riak_kv_eleveldb_backend, [
                {max_open_files, 50},
                  {data_root, "/var/lib/riak/leveldb"}
              ]},
                {be_blocks, riak_kv_bitcask_backend, [
                  {data_root, "/var/lib/riak/bitcask"}
              ]}
            ]},            

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ ls
app.config  cert.pem  key.pem  vm.args
/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.10", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.10", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.10", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.10", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default bucket settings
              {default_bucket_props, [
              {n_val,2} %% Use only a replica of 2 for this test on 3 nodes
              ]},

              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.10", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.10", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].

riak1.vm.args

## Name of the riak node
-name riak@10.100.20.10

## Cookie for distributed erlang.  All nodes in the same cluster
## should use the same cookie or they will not be able to communicate.
-setcookie riak

## Heartbeat management; auto-restarts VM if it dies or becomes unresponsive
## (Disabled by default..use with caution!)
##-heart

## Enable kernel poll and a few async threads
+K true
+A 64

## Treat error_logger warnings as warnings
+W w

## Increase number of concurrent ports/sockets
-env ERL_MAX_PORTS 64000

## Tweak GC to run more often
-env ERL_FULLSWEEP_AFTER 0

## Set the location of crash dumps
-env ERL_CRASH_DUMP /var/log/riak/erl_crash.dump

## Raise the ETS table limit
-env ERL_MAX_ETS_TABLES 256000

## Force the erlang VM to use SMP
-smp enable

## For nodes with many busy_dist_port events, Basho recommends
## raising the sender-side network distribution buffer size.
## 32MB may not be sufficient for some workloads and is a suggested
## starting point.
## The Erlang/OTP default is 1024 (1 megabyte).
## See: http://www.erlang.org/doc/man/erl.html#%2bzdbbl
##+zdbbl 32768

## Raise the default erlang process limit
+P 256000

## Erlang VM scheduler tuning.
## Prerequisite: a patched VM from Basho, or a VM compiled separately
## with this patch applied:
##     https://gist.github.com/evanmcc/a599f4c6374338ed672e
##+sfwi 500

## Begin SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT

## To enable SSL encryption of the Erlang intra-cluster communication,
## un-comment the three lines below and make certain that the paths
## point to correct PEM data files.  See docs TODO for details.

## -proto_dist inet_ssl
## -ssl_dist_opt client_certfile "/etc/riak/erlclient.pem"
## -ssl_dist_opt server_certfile "/etc/riak/erlserver.pem"

## End SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT

riak2.app.config

%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.11", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.11", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.11", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Riak CS paths
            {add_paths, ["/usr/lib/riak-cs/lib/riak_cs-1.4.0/ebin"]},

            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% Riak CS Configuration...
            {multi_backend_prefix_list, [{<<"0b:">>, be_blocks}]},
            {multi_backend_default, be_default},
            {multi_backend, [
              {be_default, riak_kv_eleveldb_backend, [
                {max_open_files, 50},
                  {data_root, "/var/lib/riak/leveldb"}
              ]},
                {be_blocks, riak_kv_bitcask_backend, [
                  {data_root, "/var/lib/riak/bitcask"}
              ]}
            ]},            

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ ls
app.config  cert.pem  key.pem  vm.args
/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.11", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.11", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.11", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.11", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default bucket settings
              {default_bucket_props, [
              {n_val,2} %% Use only a replica of 2 for this test on 3 nodes
              ]},

              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.11", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.11", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].

riak2.vm.args

## Name of the riak node
-name riak@10.100.20.11

## Cookie for distributed erlang.  All nodes in the same cluster
## should use the same cookie or they will not be able to communicate.
-setcookie riak

## Heartbeat management; auto-restarts VM if it dies or becomes unresponsive
## (Disabled by default..use with caution!)
##-heart

## Enable kernel poll and a few async threads
+K true
+A 64

## Treat error_logger warnings as warnings
+W w

## Increase number of concurrent ports/sockets
-env ERL_MAX_PORTS 64000

## Tweak GC to run more often
-env ERL_FULLSWEEP_AFTER 0

## Set the location of crash dumps
-env ERL_CRASH_DUMP /var/log/riak/erl_crash.dump

## Raise the ETS table limit
-env ERL_MAX_ETS_TABLES 256000

## Force the erlang VM to use SMP
-smp enable

## For nodes with many busy_dist_port events, Basho recommends
## raising the sender-side network distribution buffer size.
## 32MB may not be sufficient for some workloads and is a suggested
## starting point.
## The Erlang/OTP default is 1024 (1 megabyte).
## See: http://www.erlang.org/doc/man/erl.html#%2bzdbbl
##+zdbbl 32768

## Raise the default erlang process limit
+P 256000

## Erlang VM scheduler tuning.
## Prerequisite: a patched VM from Basho, or a VM compiled separately
## with this patch applied:
##     https://gist.github.com/evanmcc/a599f4c6374338ed672e
##+sfwi 500

## Begin SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT

## To enable SSL encryption of the Erlang intra-cluster communication,
## un-comment the three lines below and make certain that the paths
## point to correct PEM data files.  See docs TODO for details.

## -proto_dist inet_ssl
## -ssl_dist_opt client_certfile "/etc/riak/erlclient.pem"
## -ssl_dist_opt server_certfile "/etc/riak/erlserver.pem"

## End SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT

riak3.app.config

%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.1", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.1", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.1", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Riak CS paths
            {add_paths, ["/usr/lib/riak-cs/lib/riak_cs-1.4.0/ebin"]},

            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% Riak CS Configuration...
            {multi_backend_prefix_list, [{<<"0b:">>, be_blocks}]},
            {multi_backend_default, be_default},
            {multi_backend, [
              {be_default, riak_kv_eleveldb_backend, [
                {max_open_files, 50},
                  {data_root, "/var/lib/riak/leveldb"}
              ]},
                {be_blocks, riak_kv_bitcask_backend, [
                  {data_root, "/var/lib/riak/bitcask"}
              ]}
            ]},            

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ ls
app.config  cert.pem  key.pem  vm.args
/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.1", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.1", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.1", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].
/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ mcedit app.config

/etc/riak❯❯❯ cat app.config
%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ft=erlang ts=4 sw=4 et
[
 %% Riak Client APIs config
 {riak_api, [
            %% pb_backlog is the maximum length to which the queue of pending
            %% connections may grow. If set, it must be an integer >= 0.
            %% By default the value is 5. If you anticipate a huge number of
            %% connections being initialised *simultaneously*, set this number
            %% higher.
            %% {pb_backlog, 64},

            %% pb is a list of IP addresses and TCP ports that the Riak
            %% Protocol Buffers interface will bind.
            {pb, [ {"10.100.20.1", 8087 } ]}
            ]},

 %% Riak Core config
 {riak_core, [
              %% Default bucket settings
              {default_bucket_props, [
              {n_val,2} %% Use only a replica of 2 for this test on 3 nodes
              ]},

              %% Default location of ringstate
              {ring_state_dir, "/var/lib/riak/ring"},

              %% Default ring creation size.  Make sure it is a power of 2,
              %% e.g. 16, 32, 64, 128, 256, 512 etc
              %{ring_creation_size, 64},

              %% http is a list of IP addresses and TCP ports that the Riak
              %% HTTP interface will bind.
              {http, [ {"10.100.20.1", 8098 } ]},

              %% https is a list of IP addresses and TCP ports that the Riak
              %% HTTPS interface will bind.
              %{https, [{ "10.100.20.1", 8098 }]},

              %% Default cert and key locations for https can be overridden
              %% with the ssl config variable, for example:
              %{ssl, [
              %       {certfile, "/etc/riak/cert.pem"},
              %       {keyfile, "/etc/riak/key.pem"}
              %      ]},

              %% riak_handoff_port is the TCP port that Riak uses for
              %% intra-cluster data handoff.
              {handoff_port, 8099 },

              %% To encrypt riak_core intra-cluster data handoff traffic,
              %% uncomment the following line and edit its path to an
              %% appropriate certfile and keyfile.  (This example uses a
              %% single file with both items concatenated together.)
              %{handoff_ssl_options, [{certfile, "/tmp/erlserver.pem"}]},

              %% DTrace support
              %% Do not enable 'dtrace_support' unless your Erlang/OTP
              %% runtime is compiled to support DTrace.  DTrace is
              %% available in R15B01 (supported by the Erlang/OTP
              %% official source package) and in R14B04 via a custom
              %% source repository & branch.
              {dtrace_support, false},

              %% Health Checks
              %% If disabled, health checks registered by an application will
              %% be ignored. NOTE: this option cannot be changed at runtime.
              %% To re-enable, the setting must be changed and the node restarted.
              %% NOTE: As of Riak 1.3.2, health checks are deprecated as they
              %% may interfere with the new overload protection mechanisms.
              %% If there is a good reason to re-enable them, you must uncomment
              %% this line and also add an entry in the riak_kv section:
              %%          {riak_kv, [ ..., {enable_health_checks, true}, ...]}
              %% {enable_health_checks, true},

              %% Platform-specific installation paths (substituted by rebar)
              {platform_bin_dir, "/usr/sbin"},
              {platform_data_dir, "/var/lib/riak"},
              {platform_etc_dir, "/etc/riak"},
              {platform_lib_dir, "/usr/lib/riak/lib"},
              {platform_log_dir, "/var/log/riak"}
             ]},

 %% Riak KV config
 {riak_kv, [
            %% Storage_backend specifies the Erlang module defining the storage
            %% mechanism that will be used on this node.
            {storage_backend, riak_kv_bitcask_backend},

            %% raw_name is the first part of all URLS used by the Riak raw HTTP
            %% interface.  See riak_web.erl and raw_http_resource.erl for
            %% details.
            %{raw_name, "riak"},

            %% Enable active anti-entropy subsystem + optional debug messages:
            %%   {anti_entropy, {on|off, []}},
            %%   {anti_entropy, {on|off, [debug]}},
            {anti_entropy, {on, []}},

            %% Restrict how fast AAE can build hash trees. Building the tree
            %% for a given partition requires a full scan over that partition's
            %% data. Once built, trees stay built until they are expired.
            %% Config is of the form:
            %%   {num-builds, per-timespan-in-milliseconds}
            %% Default is 1 build per hour.
            {anti_entropy_build_limit, {1, 3600000}},

            %% Determine how often hash trees are expired after being built.
            %% Periodically expiring a hash tree ensures the on-disk hash tree
            %% data stays consistent with the actual k/v backend data. It also
            %% helps Riak identify silent disk failures and bit rot. However,
            %% expiration is not needed for normal AAE operation and should be
            %% infrequent for performance reasons. The time is specified in
            %% milliseconds. The default is 1 week.
            {anti_entropy_expire, 604800000},

            %% Limit how many AAE exchanges/builds can happen concurrently.
            {anti_entropy_concurrency, 2},

            %% The tick determines how often the AAE manager looks for work
            %% to do (building/expiring trees, triggering exchanges, etc).
            %% The default is every 15 seconds. Lowering this value will
            %% speedup the rate that all replicas are synced across the cluster.
            %% Increasing the value is not recommended.
            {anti_entropy_tick, 15000},

            %% The directory where AAE hash trees are stored.
            {anti_entropy_data_dir, "/var/lib/riak/anti_entropy"},

            %% The LevelDB options used by AAE to generate the LevelDB-backed
            %% on-disk hashtrees.
            {anti_entropy_leveldb_opts, [{write_buffer_size, 4194304},
                                         {max_open_files, 20}]},

            %% mapred_name is URL used to submit map/reduce requests to Riak.
            {mapred_name, "mapred"},

            %% mapred_2i_pipe indicates whether secondary-index
            %% MapReduce inputs are queued in parallel via their own
            %% pipe ('true'), or serially via a helper process
            %% ('false' or undefined).  Set to 'false' or leave
            %% undefined during a rolling upgrade from 1.0.
            {mapred_2i_pipe, true},

            %% Each of the following entries control how many Javascript
            %% virtual machines are available for executing map, reduce,
            %% pre- and post-commit hook functions.
            {map_js_vm_count, 8 },
            {reduce_js_vm_count, 6 },
            {hook_js_vm_count, 2 },

            %% js_max_vm_mem is the maximum amount of memory, in megabytes,
            %% allocated to the Javascript VMs. If unset, the default is
            %% 8MB.
            {js_max_vm_mem, 8},

            %% js_thread_stack is the maximum amount of thread stack, in megabyes,
            %% allocate to the Javascript VMs. If unset, the default is 16MB.
            %% NOTE: This is not the same as the C thread stack.
            {js_thread_stack, 16},

            %% js_source_dir should point to a directory containing Javascript
            %% source files which will be loaded by Riak when it initializes
            %% Javascript VMs.
            %{js_source_dir, "/tmp/js_source"},

            %% http_url_encoding determines how Riak treats URL encoded
            %% buckets, keys, and links over the REST API. When set to 'on'
            %% Riak always decodes encoded values sent as URLs and Headers.
            %% Otherwise, Riak defaults to compatibility mode where links
            %% are decoded, but buckets and keys are not. The compatibility
            %% mode will be removed in a future release.
            {http_url_encoding, on},

            %% Switch to vnode-based vclocks rather than client ids.  This
            %% significantly reduces the number of vclock entries.
            %% Only set true if *all* nodes in the cluster are upgraded to 1.0
            {vnode_vclocks, true},

            %% This option toggles compatibility of keylisting with 1.0
            %% and earlier versions.  Once a rolling upgrade to a version
            %% > 1.0 is completed for a cluster, this should be set to
            %% true for better control of memory usage during key listing
            %% operations
            {listkeys_backpressure, true},

            %% This option specifies how many of each type of fsm may exist
            %% concurrently.  This is for overload protection and is a new
            %% mechanism that obsoletes 1.3's health checks. Note that this number
            %% represents two potential processes, so +P in vm.args should be at
            %% least 3X the fsm_limit.
            {fsm_limit, 50000},

            %% object_format controls which binary representation of a riak_object
            %% is stored on disk.
            %% Current options are: v0, v1.
            %% v0: Original erlang:term_to_binary format. Higher space overhead.
            %% v1: New format for more compact storage of small values.
            {object_format, v1}
           ]},

 %% Riak Search Config
 {riak_search, [
                %% To enable Search functionality set this 'true'.
                {enabled, false}
               ]},

 %% Merge Index Config
 {merge_index, [
                %% The root dir to store search merge_index data
                {data_root, "/var/lib/riak/merge_index"},

                %% Size, in bytes, of the in-memory buffer.  When this
                %% threshold has been reached the data is transformed
                %% into a segment file which resides on disk.
                {buffer_rollover_size, 1048576},

                %% Overtime the segment files need to be compacted.
                %% This is the maximum number of segments that will be
                %% compacted at once.  A lower value will lead to
                %% quicker but more frequent compactions.
                {max_compact_segments, 20}
               ]},

 %% Bitcask Config
 {bitcask, [
             %% Configure how Bitcask writes data to disk.
             %%   erlang: Erlang's built-in file API
             %%      nif: Direct calls to the POSIX C API
             %%
             %% The NIF mode provides higher throughput for certain
             %% workloads, but has the potential to negatively impact
             %% the Erlang VM, leading to higher worst-case latencies
             %% and possible throughput collapse.
             {io_mode, erlang},
             {max_file_size, 268435456},

             %% Trigger a merge if any of the following are true:
             {frag_merge_trigger, 35}, %% fragmentation >= 35%
             {dead_bytes_merge_trigger, 134217728}, %% dead bytes > 128 MB

             %% Conditions that determine if a file will be examined during a merge:
             {frag_threshold, 20}, %% fragmentation >= 20%
             {dead_bytes_threshold, 33554432}, %% dead bytes > 32 MB
             {small_file_threshold, 10485760}, %% file is < 10MB

             {data_root, "/var/lib/riak/bitcask"}
           ]},

 %% eLevelDB Config
 {eleveldb, [
             {data_root, "/var/lib/riak/leveldb"}
            ]},

 %% Lager Config
 {lager, [
            %% What handlers to install with what arguments
            %% The defaults for the logfiles are to rotate the files when
            %% they reach 10Mb or at midnight, whichever comes first, and keep
            %% the last 5 rotations. See the lager README for a description of
            %% the time rotation format:
            %% https://github.com/basho/lager/blob/master/README.org
            %%
            %% If you wish to disable rotation, you can either set the size to 0
            %% and the rotation time to "", or instead specify a 2-tuple that only
            %% consists of {Logfile, Level}.
            %%
            %% If you wish to have riak log messages to syslog, you can use a handler
            %% like this:
            %%   {lager_syslog_backend, ["riak", daemon, info]},
            %%
            {handlers, [
                           {lager_file_backend, [
                               {"/var/log/riak/error.log", error, 10485760, "$D0", 5},
                               {"/var/log/riak/console.log", info, 10485760, "$D0", 5}
                           ]}
                       ] },

            %% Whether to write a crash log, and where.
            %% Commented/omitted/undefined means no crash logger.
            {crash_log, "/var/log/riak/crash.log"},

            %% Maximum size in bytes of events in the crash log - defaults to 65536
            {crash_log_msg_size, 65536},

            %% Maximum size of the crash log in bytes, before its rotated, set
            %% to 0 to disable rotation - default is 0
            {crash_log_size, 10485760},

            %% What time to rotate the crash log - default is no time
            %% rotation. See the lager README for a description of this format:
            %% https://github.com/basho/lager/blob/master/README.org
            {crash_log_date, "$D0"},

            %% Number of rotated crash logs to keep, 0 means keep only the
            %% current one - default is 0
            {crash_log_count, 5},

            %% Whether to redirect error_logger messages into lager - defaults to true
            {error_logger_redirect, true},

            %% maximum number of error_logger messages to handle in a second
            %% lager 2.0.0 shipped with a limit of 50, which is a little low for riak's startup
            {error_logger_hwm, 100}
        ]},

 %% riak_sysmon config
 {riak_sysmon, [
         %% To disable forwarding events of a particular type, use a
         %% limit of 0.
         {process_limit, 30},
         {port_limit, 2},

         %% Finding reasonable limits for a given workload is a matter
         %% of experimentation.
         %% NOTE: Enabling the 'gc_ms_limit' monitor (by setting non-zero)
         %%       can cause performance problems on multi-CPU systems.
         {gc_ms_limit, 0},
         {heap_word_limit, 40111000},

         %% Configure the following items to 'false' to disable logging
         %% of that event type.
         {busy_port, true},
         {busy_dist_port, true}
        ]},

 %% SASL config
 {sasl, [
         {sasl_error_logger, false}
        ]},

 %% riak_control config
 {riak_control, [
                %% Set to false to disable the admin panel.
                {enabled, false},

                %% Authentication style used for access to the admin
                %% panel. Valid styles are 'userlist' <TODO>.
                {auth, userlist},

                %% If auth is set to 'userlist' then this is the
                %% list of usernames and passwords for access to the
                %% admin panel.
                {userlist, [{"user", "pass"}
                           ]},

                %% The admin panel is broken up into multiple
                %% components, each of which is enabled or disabled
                %% by one of these settings.
                {admin, true}
                ]}
].

riak3.vm.args

## Name of the riak node
-name riak@10.100.20.1

## Cookie for distributed erlang.  All nodes in the same cluster
## should use the same cookie or they will not be able to communicate.
-setcookie riak

## Heartbeat management; auto-restarts VM if it dies or becomes unresponsive
## (Disabled by default..use with caution!)
##-heart

## Enable kernel poll and a few async threads
+K true
+A 64

## Treat error_logger warnings as warnings
+W w

## Increase number of concurrent ports/sockets
-env ERL_MAX_PORTS 64000

## Tweak GC to run more often
-env ERL_FULLSWEEP_AFTER 0

## Set the location of crash dumps
-env ERL_CRASH_DUMP /var/log/riak/erl_crash.dump

## Raise the ETS table limit
-env ERL_MAX_ETS_TABLES 256000

## Force the erlang VM to use SMP
-smp enable

## For nodes with many busy_dist_port events, Basho recommends
## raising the sender-side network distribution buffer size.
## 32MB may not be sufficient for some workloads and is a suggested
## starting point.
## The Erlang/OTP default is 1024 (1 megabyte).
## See: http://www.erlang.org/doc/man/erl.html#%2bzdbbl
##+zdbbl 32768

## Raise the default erlang process limit
+P 256000

## Erlang VM scheduler tuning.
## Prerequisite: a patched VM from Basho, or a VM compiled separately
## with this patch applied:
##     https://gist.github.com/evanmcc/a599f4c6374338ed672e
##+sfwi 500

## Begin SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT

## To enable SSL encryption of the Erlang intra-cluster communication,
## un-comment the three lines below and make certain that the paths
## point to correct PEM data files.  See docs TODO for details.

## -proto_dist inet_ssl
## -ssl_dist_opt client_certfile "/etc/riak/erlclient.pem"
## -ssl_dist_opt server_certfile "/etc/riak/erlserver.pem"

## End SSL distribution items, DO NOT DELETE OR EDIT THIS COMMENT