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| VARNISHD(1) VARNISHD(1) | |
| NAME | |
| varnishd - HTTP accelerator daemon | |
| SYNOPSIS | |
| varnishd | |
| [-a [name=][listen_address[,PROTO]] [-b [host[:port]|path]] [-C] | |
| [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i | |
| identity] [-j jail[,jailoptions]] [-l vsl] [-M address:port] [-n | |
| workdir] [-P file] [-p param=value] [-r param[,param...]] [-S | |
| secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t | |
| TTL] [-V] [-W waiter] | |
| varnishd [-x parameter|vsl|cli|builtin|optstring] | |
| varnishd [-?] | |
| DESCRIPTION | |
| The varnishd daemon accepts HTTP requests from clients, passes them on | |
| to a backend server and caches the returned documents to better satisfy | |
| future requests for the same document. | |
| OPTIONS | |
| Basic options | |
| -a_<[name=][listen_address[,PROTO]]> | |
| Accept for client requests on the specified listen_address (see | |
| below). | |
| Name is referenced in logs. If name is not specified, "a0", | |
| "a1", etc. is used. | |
| PROTO can be "HTTP" (the default) or "PROXY". Both version 1 | |
| and 2 of the proxy protocol can be used. | |
| Multiple -a arguments are allowed. | |
| If no -a argument is given, the default -a :80 will listen to | |
| all IPv4 and IPv6 interfaces. | |
| -a_<[name=][ip_address][:port][,PROTO]> | |
| The ip_address can be a host name ("localhost"), an IPv4 | |
| dotted-quad ("127.0.0.1") or an IPv6 address enclosed in square | |
| brackets ("[::1]") | |
| If port is not specified, port 80 (http) is used. | |
| At least one of ip_address or port is required. | |
| -a_<[name=][path][,PROTO][,user=name][,group=name][,mode=octal]> | |
| (VCL4.1 and higher) | |
| Accept connections on a Unix domain socket. Path must be | |
| absolute ("/path/to/listen.sock") or "@" followed by the name of | |
| an abstract socket ("@myvarnishd"). | |
| The user, group and mode sub-arguments may be used to specify | |
| the permissions of the socket file -- use names for user and | |
| group, and a 3-digit octal value for mode. These sub-arguments | |
| do not apply to abstract sockets. | |
| -b_<[host[:port]|path]> | |
| Use the specified host as backend server. If port is not | |
| specified, the default is 8080. | |
| If the value of -b begins with /, it is interpreted as the | |
| absolute path of a Unix domain socket to which Varnish connects. | |
| In that case, the value of -b must satisfy the conditions | |
| required for the .path field of a backend declaration, see | |
| vcl(7). Backends with Unix socket addresses may only be used | |
| with VCL versions >= 4.1. | |
| -b can be used only once, and not together with f. | |
| -f_config | |
| Use the specified VCL configuration file instead of the builtin | |
| default. See vcl(7) for details on VCL syntax. | |
| If a single -f option is used, then the VCL instance loaded from | |
| the file is named "boot" and immediately becomes active. If more | |
| than one -f option is used, the VCL instances are named "boot0", | |
| "boot1" and so forth, in the order corresponding to the -f | |
| arguments, and the last one is named "boot", which becomes | |
| active. | |
| Either -b or one or more -f options must be specified, but not | |
| both, and they cannot both be left out, unless -d is used to | |
| start varnishd in debugging mode. If the empty string is | |
| specified as the sole -f option, then varnishd starts without | |
| starting the worker process, and the management process will | |
| accept CLI commands. You can also combine an empty -f option | |
| with an initialization script (-I option) and the child process | |
| will be started if there is an active VCL at the end of the | |
| initialization. | |
| When used with a relative file name, config is searched in the | |
| vcl_path. It is possible to set this path prior to using -f | |
| options with a -p option. During startup, varnishd doesn't | |
| complain about unsafe VCL paths: unlike the varnish-cli(7) that | |
| could later be accessed remotely, starting varnishd requires | |
| local privileges. | |
| -n_workdir | |
| Runtime directory for the shared memory, compiled VCLs etc. | |
| In performance critical applications, this directory should be | |
| on a RAM backed filesystem. | |
| Relative paths will be appended to /var/run/ (NB: Binary | |
| packages of Varnish may have adjusted this to the platform.) | |
| The default value is /var/run/varnishd (NB: as above.) | |
| Documentation options | |
| For these options, varnishd prints information to standard output and | |
| exits. When a -x option is used, it must be the only option (it outputs | |
| documentation in reStructuredText, aka RST). | |
| -? | |
| Print the usage message. | |
| -x_parameter | |
| Print documentation of the runtime parameters (-p options), see | |
| List of Parameters. | |
| -x_vsl Print documentation of the tags used in the Varnish shared | |
| memory log, see vsl(7). | |
| -x_cli Print documentation of the command line interface, see | |
| varnish-cli(7). | |
| -x_builtin | |
| Print the contents of the default VCL program builtin.vcl. | |
| -x_optstring | |
| Print the optstring parameter to getopt(3) to help writing | |
| wrapper scripts. | |
| Operations options | |
| -F Do not fork, run in the foreground. Only one of -F or -d can be | |
| specified, and -F cannot be used together with -C. | |
| -T_<address[:port]> | |
| Offer a management interface on the specified address and port. | |
| See varnish-cli(7) for documentation of the management commands. | |
| To disable the management interface use none. | |
| -M_<address:port> | |
| Connect to this port and offer the command line interface. | |
| Think of it as a reverse shell. When running with -M and there | |
| is no backend defined the child process (the cache) will not | |
| start initially. | |
| -P_file | |
| Write the PID of the process to the specified file. | |
| -i_identity | |
| Specify the identity of the Varnish server. This can be accessed | |
| using server.identity from VCL. | |
| The server identity is used for the received-by field of Via | |
| headers generated by Varnish. For this reason, it must be a | |
| valid token as defined by the HTTP grammar. | |
| If not specified the output of gethostname(3) is used, in which | |
| case the syntax is assumed to be correct. | |
| -I_clifile | |
| Execute the management commands in the file given as clifile | |
| before the the worker process starts, see CLI Command File. | |
| Tuning options | |
| -t_TTL Specifies the default time to live (TTL) for cached objects. | |
| This is a shortcut for specifying the default_ttl run-time | |
| parameter. | |
| -p_<param=value> | |
| Set the parameter specified by param to the specified value, see | |
| List of Parameters for details. This option can be used multiple | |
| times to specify multiple parameters. | |
| -s_<[name=]type[,options]> | |
| Use the specified storage backend. See Storage Backend section. | |
| This option can be used multiple times to specify multiple | |
| storage files. Name is referenced in logs, VCL, statistics, etc. | |
| If name is not specified, "s0", "s1" and so forth is used. | |
| -l_<vsl> | |
| Specifies size of the space for the VSL records, shorthand for | |
| -p vsl_space=<vsl>. Scaling suffixes like 'K' and 'M' can be | |
| used up to (G)igabytes. See vsl_space for more information. | |
| Security options | |
| -r_<param[,param...]> | |
| Make the listed parameters read only. This gives the system | |
| administrator a way to limit what the Varnish CLI can do. | |
| Consider making parameters such as cc_command, | |
| vcc_allow_inline_c and vmod_path read only as these can | |
| potentially be used to escalate privileges from the CLI. | |
| -S_secret-file | |
| Path to a file containing a secret used for authorizing access | |
| to the management port. To disable authentication use none. | |
| If this argument is not provided, a secret drawn from the system | |
| PRNG will be written to a file called _.secret in the working | |
| directory (see opt_n) with default ownership and permissions of | |
| the user having started varnish. | |
| Thus, users wishing to delegate control over varnish will | |
| probably want to create a custom secret file with appropriate | |
| permissions (ie. readable by a unix group to delegate control | |
| to). | |
| -j_<jail[,jailoptions]> | |
| Specify the jailing mechanism to use. See Jail section. | |
| Advanced, development and debugging options | |
| -d Enables debugging mode: The parent process runs in the | |
| foreground with a CLI connection on stdin/stdout, and the child | |
| process must be started explicitly with a CLI command. | |
| Terminating the parent process will also terminate the child. | |
| Only one of -d or -F can be specified, and -d cannot be used | |
| together with -C. | |
| -C Print VCL code compiled to C language and exit. Specify the VCL | |
| file to compile with the -f option. Either -f or -b must be used | |
| with -C, and -C cannot be used with -F or -d. | |
| -V Display the version number and exit. This must be the only | |
| option. | |
| -h_<type[,options]> | |
| Specifies the hash algorithm. See Hash Algorithm section for a | |
| list of supported algorithms. | |
| -W_waiter | |
| Specifies the waiter type to use. | |
| Hash Algorithm | |
| The following hash algorithms are available: | |
| -h_critbit | |
| self-scaling tree structure. The default hash algorithm in | |
| Varnish Cache 2.1 and onwards. In comparison to a more | |
| traditional B tree the critbit tree is almost completely | |
| lockless. Do not change this unless you are certain what you're | |
| doing. | |
| -h_simple_list | |
| A simple doubly-linked list. Not recommended for production | |
| use. | |
| -h_<classic[,buckets]> | |
| A standard hash table. The hash key is the CRC32 of the object's | |
| URL modulo the size of the hash table. Each table entry points | |
| to a list of elements which share the same hash key. The buckets | |
| parameter specifies the number of entries in the hash table. | |
| The default is 16383. | |
| Storage Backend | |
| The argument format to define storage backends is: | |
| -s_<[name]=kind[,options]> | |
| If name is omitted, Varnish will name storages sN, starting with | |
| s0 and incrementing N for every new storage. | |
| For kind and options see details below. | |
| Storages can be used in vcl as storage.name, so, for example if | |
| myStorage was defined by -s myStorage=malloc,5G, it could be used in | |
| VCL like so: | |
| set beresp.storage = storage.myStorage; | |
| A special name is Transient which is the default storage for | |
| uncacheable objects as resulting from a pass, hit-for-miss or | |
| hit-for-pass. | |
| If no -s options are given, the default is: | |
| -s default,100m | |
| If no Transient storage is defined, the default is an unbound default | |
| storage as if defined as: | |
| -s Transient=default | |
| The following storage types and options are available: | |
| -s_<default[,size]> | |
| The default storage type resolves to umem where available and | |
| malloc otherwise. | |
| -s_<malloc[,size]> | |
| malloc is a memory based backend. | |
| -s_<umem[,size]> | |
| umem is a storage backend which is more efficient than malloc on | |
| platforms where it is available. | |
| See the section on umem in chapter Storage backends of The | |
| Varnish Users Guide for details. | |
| -s_<file,path[,size[,granularity[,advice]]]> | |
| The file backend stores data in a file on disk. The file will be | |
| accessed using mmap. Note that this storage provide no cache | |
| persistence. | |
| The path is mandatory. If path points to a directory, a | |
| temporary file will be created in that directory and immediately | |
| unlinked. If path points to a non-existing file, the file will | |
| be created. | |
| If size is omitted, and path points to an existing file with a | |
| size greater than zero, the size of that file will be used. If | |
| not, an error is reported. | |
| Granularity sets the allocation block size. Defaults to the | |
| system page size or the filesystem block size, whichever is | |
| larger. | |
| Advice tells the kernel how varnishd expects to use this mapped | |
| region so that the kernel can choose the appropriate read-ahead | |
| and caching techniques. Possible values are normal, random and | |
| sequential, corresponding to MADV_NORMAL, MADV_RANDOM and | |
| MADV_SEQUENTIAL madvise() advice argument, respectively. | |
| Defaults to random. | |
| -s_<persistent,path,size> | |
| Persistent storage. Varnish will store objects in a file in a | |
| manner that will secure the survival of most of the objects in | |
| the event of a planned or unplanned shutdown of Varnish. The | |
| persistent storage backend has multiple issues with it and will | |
| likely be removed from a future version of Varnish. | |
| Jail | |
| Varnish jails are a generalization over various platform specific | |
| methods to reduce the privileges of varnish processes. They may have | |
| specific options. Available jails are: | |
| -j_<solaris[,worker=`privspec`]> | |
| Reduce privileges(5) for varnishd and sub-processes to the | |
| minimally required set. Only available on platforms which have | |
| the setppriv(2) call. | |
| The optional worker argument can be used to pass a | |
| privilege-specification (see ppriv(1)) by which to extend the | |
| effective set of the varnish worker process. While extended | |
| privileges may be required by custom vmods, not using the worker | |
| option is always more secure. | |
| Example to grant basic privileges to the worker process: | |
| -j solaris,worker=basic | |
| -j_<unix[,user=`user`][,ccgroup=`group`][,workuser=`user`]> | |
| Default on all other platforms when varnishd is started with an | |
| effective uid of 0 ("as root"). | |
| With the unix jail mechanism activated, varnish will switch to | |
| an alternative user for subprocesses and change the effective | |
| uid of the master process whenever possible. | |
| The optional user argument specifies which alternative user to | |
| use. It defaults to varnish. | |
| The optional ccgroup argument specifies a group to add to | |
| varnish subprocesses requiring access to a c-compiler. There is | |
| no default. | |
| The optional workuser argument specifies an alternative user to | |
| use for the worker process. It defaults to vcache. | |
| The users given for the user and workuser arguments need to have | |
| the same primary ("login") group. | |
| To set up a system for the default users with a group name | |
| varnish, shell commands similar to these may be used: | |
| groupadd varnish | |
| useradd -g varnish -d /nonexistent -s /bin/false \ | |
| -c "Varnish-Cache Daemon User" varnish | |
| useradd -g varnish -d /nonexistent -s /bin/false \ | |
| -c "Varnish-Cache Worker User" vcache | |
| -j_none | |
| last resort jail choice: With jail mechanism none, varnish will | |
| run all processes with the privileges it was started with. | |
| Management Interface | |
| If the -T option was specified, varnishd will offer a command-line | |
| management interface on the specified address and port. The | |
| recommended way of connecting to the command-line management interface | |
| is through varnishadm(1). | |
| The commands available are documented in varnish-cli(7). | |
| CLI Command File | |
| The -I option makes it possible to run arbitrary management commands | |
| when varnishd is launched, before the worker process is started. In | |
| particular, this is the way to load configurations, apply labels to | |
| them, and make a VCL instance active that uses those labels on startup: | |
| vcl.load panic /etc/varnish_panic.vcl | |
| vcl.load siteA0 /etc/varnish_siteA.vcl | |
| vcl.load siteB0 /etc/varnish_siteB.vcl | |
| vcl.load siteC0 /etc/varnish_siteC.vcl | |
| vcl.label siteA siteA0 | |
| vcl.label siteB siteB0 | |
| vcl.label siteC siteC0 | |
| vcl.load main /etc/varnish_main.vcl | |
| vcl.use main | |
| Every line in the file, including the last line, must be terminated by | |
| a newline or carriage return. | |
| If a command in the file is prefixed with '-', failure will not abort | |
| the startup. | |
| Note that it is necessary to include an explicit vcl.use command to | |
| select which VCL should be the active VCL when relying on CLI Command | |
| File to load the configurations at startup. | |
| RUN TIME PARAMETERS | |
| Run Time Parameter Flags | |
| Runtime parameters are marked with shorthand flags to avoid repeating | |
| the same text over and over in the table below. The meaning of the | |
| flags are: | |
| • experimental | |
| We have no solid information about good/bad/optimal values for this | |
| parameter. Feedback with experience and observations are most | |
| welcome. | |
| • delayed | |
| This parameter can be changed on the fly, but will not take effect | |
| immediately. | |
| • restart | |
| The worker process must be stopped and restarted, before this | |
| parameter takes effect. | |
| • reload | |
| The VCL programs must be reloaded for this parameter to take effect. | |
| • wizard | |
| Do not touch unless you really know what you're doing. | |
| • only_root | |
| Only works if varnishd is running as root. | |
| Default Value Exceptions on 32 bit Systems | |
| Be aware that on 32 bit systems, certain default or maximum values are | |
| reduced relative to the values listed below, in order to conserve VM | |
| space: | |
| • workspace_client: 24k | |
| • workspace_backend: 20k | |
| • http_resp_size: 8k | |
| • http_req_size: 12k | |
| • gzip_buffer: 4k | |
| • vsl_buffer: 4k | |
| • vsl_space: 1G (maximum) | |
| • thread_pool_stack: 64k | |
| List of Parameters | |
| This text is produced from the same text you will find in the CLI if | |
| you use the param.show command: | |
| accept_filter | |
| NB: This parameter depends on a feature which is not available on all | |
| platforms. | |
| • Units: bool | |
| • Default: on (if your platform supports accept filters) | |
| Enable kernel accept-filters. This may require a kernel module to be | |
| loaded to have an effect when enabled. | |
| Enabling accept_filter may prevent some requests to reach Varnish in | |
| the first place. Malformed requests may go unnoticed and not increase | |
| the client_req_400 counter. GET or HEAD requests with a body may be | |
| blocked altogether. | |
| acceptor_sleep_decay | |
| • Default: 0.9 | |
| • Minimum: 0 | |
| • Maximum: 1 | |
| • Flags: experimental | |
| If we run out of resources, such as file descriptors or worker threads, | |
| the acceptor will sleep between accepts. This parameter | |
| (multiplicatively) reduce the sleep duration for each successful | |
| accept. (ie: 0.9 = reduce by 10%) | |
| acceptor_sleep_incr | |
| • Units: seconds | |
| • Default: 0.000 | |
| • Minimum: 0.000 | |
| • Maximum: 1.000 | |
| • Flags: experimental | |
| If we run out of resources, such as file descriptors or worker threads, | |
| the acceptor will sleep between accepts. This parameter control how | |
| much longer we sleep, each time we fail to accept a new connection. | |
| acceptor_sleep_max | |
| • Units: seconds | |
| • Default: 0.050 | |
| • Minimum: 0.000 | |
| • Maximum: 10.000 | |
| • Flags: experimental | |
| If we run out of resources, such as file descriptors or worker threads, | |
| the acceptor will sleep between accepts. This parameter limits how | |
| long it can sleep between attempts to accept new connections. | |
| auto_restart | |
| • Units: bool | |
| • Default: on | |
| Automatically restart the child/worker process if it dies. | |
| backend_idle_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 1.000 | |
| Timeout before we close unused backend connections. | |
| backend_local_error_holddown | |
| • Units: seconds | |
| • Default: 10.000 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| When connecting to backends, certain error codes (EADDRNOTAVAIL, | |
| EACCESS, EPERM) signal a local resource shortage or configuration issue | |
| for which retrying connection attempts may worsen the situation due to | |
| the complexity of the operations involved in the kernel. This | |
| parameter prevents repeated connection attempts for the configured | |
| duration. | |
| backend_remote_error_holddown | |
| • Units: seconds | |
| • Default: 0.250 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| When connecting to backends, certain error codes (ECONNREFUSED, | |
| ENETUNREACH) signal fundamental connection issues such as the backend | |
| not accepting connections or routing problems for which repeated | |
| connection attempts are considered useless This parameter prevents | |
| repeated connection attempts for the configured duration. | |
| ban_cutoff | |
| • Units: bans | |
| • Default: 0 | |
| • Minimum: 0 | |
| • Flags: experimental | |
| Expurge long tail content from the cache to keep the number of bans | |
| below this value. 0 disables. | |
| When this parameter is set to a non-zero value, the ban lurker | |
| continues to work the ban list as usual top to bottom, but when it | |
| reaches the ban_cutoff-th ban, it treats all objects as if they matched | |
| a ban and expurges them from cache. As actively used objects get tested | |
| against the ban list at request time and thus are likely to be | |
| associated with bans near the top of the ban list, with ban_cutoff, | |
| least recently accessed objects (the "long tail") are removed. | |
| This parameter is a safety net to avoid bad response times due to bans | |
| being tested at lookup time. Setting a cutoff trades response time for | |
| cache efficiency. The recommended value is proportional to | |
| rate(bans_lurker_tests_tested) / n_objects while the ban lurker is | |
| working, which is the number of bans the system can sustain. The | |
| additional latency due to request ban testing is in the order of | |
| ban_cutoff / rate(bans_lurker_tests_tested). For example, for | |
| rate(bans_lurker_tests_tested) = 2M/s and a tolerable latency of 100ms, | |
| a good value for ban_cutoff may be 200K. | |
| ban_dups | |
| • Units: bool | |
| • Default: on | |
| Eliminate older identical bans when a new ban is added. This saves CPU | |
| cycles by not comparing objects to identical bans. This is a waste of | |
| time if you have many bans which are never identical. | |
| ban_lurker_age | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| The ban lurker will ignore bans until they are this old. When a ban is | |
| added, the active traffic will be tested against it as part of object | |
| lookup. Because many applications issue bans in bursts, this parameter | |
| holds the ban-lurker off until the rush is over. This should be set to | |
| the approximate time which a ban-burst takes. | |
| ban_lurker_batch | |
| • Default: 1000 | |
| • Minimum: 1 | |
| The ban lurker sleeps ${ban_lurker_sleep} after examining this many | |
| objects. Use this to pace the ban-lurker if it eats too many | |
| resources. | |
| ban_lurker_holdoff | |
| • Units: seconds | |
| • Default: 0.010 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| How long the ban lurker sleeps when giving way to lookup due to lock | |
| contention. | |
| ban_lurker_sleep | |
| • Units: seconds | |
| • Default: 0.010 | |
| • Minimum: 0.000 | |
| How long the ban lurker sleeps after examining ${ban_lurker_batch} | |
| objects. Use this to pace the ban-lurker if it eats too many | |
| resources. A value of zero will disable the ban lurker entirely. | |
| between_bytes_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| We only wait for this many seconds between bytes received from the | |
| backend before giving up the fetch. VCL values, per backend or per | |
| backend request take precedence. This parameter does not apply to | |
| pipe'ed requests. | |
| cc_command | |
| NB: The actual default value for this parameter depends on the Varnish | |
| build environment and options. | |
| • Default: exec $CC $CFLAGS %w -shared -o %o %s | |
| • Flags: must_reload | |
| The command used for compiling the C source code to a dlopen(3) | |
| loadable object. The following expansions can be used: | |
| • %s: the source file name | |
| • %o: the output file name | |
| • %w: the cc_warnings parameter | |
| • %d: the raw default cc_command | |
| • %D: the expanded default cc_command | |
| • %n: the working directory (-n option) | |
| • %%: a percent sign | |
| Unknown percent expansion sequences are ignored, and to avoid future | |
| incompatibilities percent characters should be escaped with a double | |
| percent sequence. | |
| The %d and %D expansions allow passing the parameter's default value to | |
| a wrapper script to perform additional processing. | |
| cc_warnings | |
| NB: The actual default value for this parameter depends on the Varnish | |
| build environment and options. | |
| • Default: -Wall -Werror | |
| • Flags: must_reload | |
| Warnings used when compiling the C source code with the cc_command | |
| parameter. By default, VCL is compiled with the same set of warnings as | |
| Varnish itself. | |
| cli_limit | |
| • Units: bytes | |
| • Default: 48k | |
| • Minimum: 128b | |
| • Maximum: 99999999b | |
| Maximum size of CLI response. If the response exceeds this limit, the | |
| response code will be 201 instead of 200 and the last line will | |
| indicate the truncation. | |
| cli_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| Timeout for the child's replies to CLI requests from the mgt_param. | |
| clock_skew | |
| • Units: seconds | |
| • Default: 10 | |
| • Minimum: 0 | |
| How much clockskew we are willing to accept between the backend and our | |
| own clock. | |
| clock_step | |
| • Units: seconds | |
| • Default: 1.000 | |
| • Minimum: 0.000 | |
| How much observed clock step we are willing to accept before we panic. | |
| connect_timeout | |
| • Units: seconds | |
| • Default: 3.500 | |
| • Minimum: 0.000 | |
| Default connection timeout for backend connections. We only try to | |
| connect to the backend for this many seconds before giving up. VCL can | |
| override this default value for each backend and backend request. | |
| critbit_cooloff | |
| • Units: seconds | |
| • Default: 180.000 | |
| • Minimum: 60.000 | |
| • Maximum: 254.000 | |
| • Flags: wizard | |
| How long the critbit hasher keeps deleted objheads on the cooloff list. | |
| debug | |
| • Default: none | |
| Enable/Disable various kinds of debugging. | |
| none Disable all debugging | |
| Use +/- prefix to set/reset individual bits: | |
| req_state | |
| VSL Request state engine | |
| workspace | |
| VSL Workspace operations | |
| waitinglist | |
| VSL Waitinglist events | |
| syncvsl | |
| Make VSL synchronous | |
| hashedge | |
| Edge cases in Hash | |
| vclrel Rapid VCL release | |
| lurker VSL Ban lurker | |
| esi_chop | |
| Chop ESI fetch to bits | |
| flush_head | |
| Flush after http1 head | |
| vtc_mode | |
| Varnishtest Mode | |
| witness | |
| Emit WITNESS lock records | |
| vsm_keep | |
| Keep the VSM file on restart | |
| slow_acceptor | |
| Slow down Acceptor | |
| h2_nocheck | |
| Disable various H2 checks | |
| vmod_so_keep | |
| Keep copied VMOD libraries | |
| processors | |
| Fetch/Deliver processors | |
| protocol | |
| Protocol debugging | |
| vcl_keep | |
| Keep VCL C and so files | |
| lck Additional lock statistics | |
| default_grace | |
| • Units: seconds | |
| • Default: 10s | |
| • Minimum: 0.000 | |
| • Flags: obj_sticky | |
| Default grace period. We will deliver an object this long after it has | |
| expired, provided another thread is attempting to get a new copy. | |
| default_keep | |
| • Units: seconds | |
| • Default: 0s | |
| • Minimum: 0.000 | |
| • Flags: obj_sticky | |
| Default keep period. We will keep a useless object around this long, | |
| making it available for conditional backend fetches. That means that | |
| the object will be removed from the cache at the end of ttl+grace+keep. | |
| default_ttl | |
| • Units: seconds | |
| • Default: 2m | |
| • Minimum: 0.000 | |
| • Flags: obj_sticky | |
| The TTL assigned to objects if neither the backend nor the VCL code | |
| assigns one. | |
| experimental | |
| • Default: none | |
| Enable/Disable experimental features. | |
| none Disable all experimental features | |
| Use +/- prefix to set/reset individual bits: | |
| drop_pools | |
| Drop thread pools | |
| feature | |
| • Default: +validate_headers | |
| Enable/Disable various minor features. | |
| default | |
| Set default value | |
| none Disable all features. | |
| Use +/- prefix to enable/disable individual feature: | |
| http2 Enable HTTP/2 protocol support. | |
| short_panic | |
| Short panic message. | |
| no_coredump | |
| No coredumps. Must be set before child process starts. | |
| https_scheme | |
| Extract host from full URI in the HTTP/1 request line, if the | |
| scheme is https. | |
| http_date_postel | |
| Tolerate non compliant timestamp headers like Date, | |
| Last-Modified, Expires etc. | |
| esi_ignore_https | |
| Convert <esi:include src"https://... to http://... | |
| esi_disable_xml_check | |
| Allow ESI processing on non-XML ESI bodies | |
| esi_ignore_other_elements | |
| Ignore XML syntax errors in ESI bodies. | |
| esi_remove_bom | |
| Ignore UTF-8 BOM in ESI bodies. | |
| esi_include_onerror | |
| Parse the onerror attribute of <esi:include> tags. | |
| wait_silo | |
| Wait for persistent silos to completely load before serving | |
| requests. | |
| validate_headers | |
| Validate all header set operations to conform to RFC7230. | |
| busy_stats_rate | |
| Make busy workers comply with thread_stats_rate. | |
| fetch_chunksize | |
| • Units: bytes | |
| • Default: 16k | |
| • Minimum: 4k | |
| • Flags: experimental | |
| The default chunksize used by fetcher. This should be bigger than the | |
| majority of objects with short TTLs. Internal limits in the | |
| storage_file module makes increases above 128kb a dubious idea. | |
| fetch_maxchunksize | |
| • Units: bytes | |
| • Default: 0.25G | |
| • Minimum: 64k | |
| • Flags: experimental | |
| The maximum chunksize we attempt to allocate from storage. Making this | |
| too large may cause delays and storage fragmentation. | |
| first_byte_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| Default timeout for receiving first byte from backend. We only wait for | |
| this many seconds for the first byte before giving up. VCL can | |
| override this default value for each backend and backend request. This | |
| parameter does not apply to pipe'ed requests. | |
| gzip_buffer | |
| • Units: bytes | |
| • Default: 32k | |
| • Minimum: 2k | |
| • Flags: experimental | |
| Size of malloc buffer used for gzip processing. These buffers are used | |
| for in-transit data, for instance gunzip'ed data being sent to a | |
| client.Making this space to small results in more overhead, writes to | |
| sockets etc, making it too big is probably just a waste of memory. | |
| gzip_level | |
| • Default: 6 | |
| • Minimum: 0 | |
| • Maximum: 9 | |
| Gzip compression level: 0=debug, 1=fast, 9=best | |
| gzip_memlevel | |
| • Default: 8 | |
| • Minimum: 1 | |
| • Maximum: 9 | |
| Gzip memory level 1=slow/least, 9=fast/most compression. Memory impact | |
| is 1=1k, 2=2k, ... 9=256k. | |
| h2_header_table_size | |
| • Units: bytes | |
| • Default: 4k | |
| • Minimum: 0b | |
| HTTP2 header table size. This is the size that will be used for the | |
| HPACK dynamic decoding table. | |
| h2_initial_window_size | |
| • Units: bytes | |
| • Default: 65535b | |
| • Minimum: 65535b | |
| • Maximum: 2147483647b | |
| HTTP2 initial flow control window size. | |
| h2_max_concurrent_streams | |
| • Units: streams | |
| • Default: 100 | |
| • Minimum: 0 | |
| HTTP2 Maximum number of concurrent streams. This is the number of | |
| requests that can be active at the same time for a single HTTP2 | |
| connection. | |
| h2_max_frame_size | |
| • Units: bytes | |
| • Default: 16k | |
| • Minimum: 16k | |
| • Maximum: 16777215b | |
| HTTP2 maximum per frame payload size we are willing to accept. | |
| h2_max_header_list_size | |
| • Units: bytes | |
| • Default: 2147483647b | |
| • Minimum: 0b | |
| HTTP2 maximum size of an uncompressed header list. | |
| h2_rx_window_increment | |
| • Units: bytes | |
| • Default: 1M | |
| • Minimum: 1M | |
| • Maximum: 1G | |
| • Flags: wizard | |
| HTTP2 Receive Window Increments. How big credits we send in | |
| WINDOW_UPDATE frames Only affects incoming request bodies (ie: POST, | |
| PUT etc.) | |
| h2_rx_window_low_water | |
| • Units: bytes | |
| • Default: 10M | |
| • Minimum: 65535b | |
| • Maximum: 1G | |
| • Flags: wizard | |
| HTTP2 Receive Window low water mark. We try to keep the window at | |
| least this big Only affects incoming request bodies (ie: POST, PUT | |
| etc.) | |
| h2_rxbuf_storage | |
| • Default: Transient | |
| • Flags: must_restart | |
| The name of the storage backend that HTTP/2 receive buffers should be | |
| allocated from. | |
| http1_iovs | |
| • Units: struct iovec (=16 bytes) | |
| • Default: 64 | |
| • Minimum: 5 | |
| • Maximum: 1024 | |
| • Flags: wizard | |
| Number of io vectors to allocate for HTTP1 protocol transmission. A | |
| HTTP1 header needs 7 + 2 per HTTP header field. Allocated from | |
| workspace_thread. | |
| http_gzip_support | |
| • Units: bool | |
| • Default: on | |
| Enable gzip support. When enabled Varnish request compressed objects | |
| from the backend and store them compressed. If a client does not | |
| support gzip encoding Varnish will uncompress compressed objects on | |
| demand. Varnish will also rewrite the Accept-Encoding header of clients | |
| indicating support for gzip to: | |
| Accept-Encoding: gzip | |
| Clients that do not support gzip will have their Accept-Encoding header | |
| removed. For more information on how gzip is implemented please see the | |
| chapter on gzip in the Varnish reference. | |
| When gzip support is disabled the variables beresp.do_gzip and | |
| beresp.do_gunzip have no effect in VCL. | |
| http_max_hdr | |
| • Units: header lines | |
| • Default: 64 | |
| • Minimum: 32 | |
| • Maximum: 65535 | |
| Maximum number of HTTP header lines we allow in | |
| {req|resp|bereq|beresp}.http (obj.http is autosized to the exact number | |
| of headers). Cheap, ~20 bytes, in terms of workspace memory. Note | |
| that the first line occupies five header lines. | |
| http_range_support | |
| • Units: bool | |
| • Default: on | |
| Enable support for HTTP Range headers. | |
| http_req_hdr_len | |
| • Units: bytes | |
| • Default: 8k | |
| • Minimum: 40b | |
| Maximum length of any HTTP client request header we will allow. The | |
| limit is inclusive its continuation lines. | |
| http_req_size | |
| • Units: bytes | |
| • Default: 32k | |
| • Minimum: 0.25k | |
| Maximum number of bytes of HTTP client request we will deal with. This | |
| is a limit on all bytes up to the double blank line which ends the HTTP | |
| request. The memory for the request is allocated from the client | |
| workspace (param: workspace_client) and this parameter limits how much | |
| of that the request is allowed to take up. | |
| http_resp_hdr_len | |
| • Units: bytes | |
| • Default: 8k | |
| • Minimum: 40b | |
| Maximum length of any HTTP backend response header we will allow. The | |
| limit is inclusive its continuation lines. | |
| http_resp_size | |
| • Units: bytes | |
| • Default: 32k | |
| • Minimum: 0.25k | |
| Maximum number of bytes of HTTP backend response we will deal with. | |
| This is a limit on all bytes up to the double blank line which ends the | |
| HTTP response. The memory for the response is allocated from the | |
| backend workspace (param: workspace_backend) and this parameter limits | |
| how much of that the response is allowed to take up. | |
| idle_send_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| • Flags: delayed | |
| Send timeout for individual pieces of data on client connections. May | |
| get extended if 'send_timeout' applies. | |
| When this timeout is hit, the session is closed. | |
| See the man page for setsockopt(2) or socket(7) under SO_SNDTIMEO for | |
| more information. | |
| listen_depth | |
| • Units: connections | |
| • Default: 1024 | |
| • Minimum: 0 | |
| • Flags: must_restart | |
| Listen queue depth. | |
| lru_interval | |
| • Units: seconds | |
| • Default: 2.000 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| Grace period before object moves on LRU list. Objects are only moved | |
| to the front of the LRU list if they have not been moved there already | |
| inside this timeout period. This reduces the amount of lock operations | |
| necessary for LRU list access. | |
| max_esi_depth | |
| • Units: levels | |
| • Default: 5 | |
| • Minimum: 0 | |
| Maximum depth of esi:include processing. | |
| max_restarts | |
| • Units: restarts | |
| • Default: 4 | |
| • Minimum: 0 | |
| Upper limit on how many times a request can restart. | |
| max_retries | |
| • Units: retries | |
| • Default: 4 | |
| • Minimum: 0 | |
| Upper limit on how many times a backend fetch can retry. | |
| max_vcl | |
| • Default: 100 | |
| • Minimum: 0 | |
| Threshold of loaded VCL programs. (VCL labels are not counted.) | |
| Parameter max_vcl_handling determines behaviour. | |
| max_vcl_handling | |
| • Default: 1 | |
| • Minimum: 0 | |
| • Maximum: 2 | |
| Behaviour when attempting to exceed max_vcl loaded VCL. | |
| • 0 - Ignore max_vcl parameter. | |
| • 1 - Issue warning. | |
| • 2 - Refuse loading VCLs. | |
| nuke_limit | |
| • Units: allocations | |
| • Default: 50 | |
| • Minimum: 0 | |
| • Flags: experimental | |
| Maximum number of objects we attempt to nuke in order to make space for | |
| a object body. | |
| pcre2_depth_limit | |
| • Default: 20 | |
| • Minimum: 1 | |
| The recursion depth-limit for the internal match logic in a | |
| pcre2_match(). | |
| (See: pcre2_set_depth_limit() in pcre2 docs.) | |
| This puts an upper limit on the amount of stack used by PCRE2 for | |
| certain classes of regular expressions. | |
| We have set the default value low in order to prevent crashes, at the | |
| cost of possible regexp matching failures. | |
| Matching failures will show up in the log as VCL_Error messages. | |
| pcre2_jit_compilation | |
| • Units: bool | |
| • Default: on | |
| Use the pcre2 JIT compiler if available. | |
| pcre2_match_limit | |
| • Default: 10000 | |
| • Minimum: 1 | |
| The limit for the number of calls to the internal match logic in | |
| pcre2_match(). | |
| (See: pcre2_set_match_limit() in pcre2 docs.) | |
| This parameter limits how much CPU time regular expression matching can | |
| soak up. | |
| ping_interval | |
| • Units: seconds | |
| • Default: 3 | |
| • Minimum: 0 | |
| • Flags: must_restart | |
| Interval between pings from parent to child. Zero will disable pinging | |
| entirely, which makes it possible to attach a debugger to the child. | |
| pipe_sess_max | |
| • Units: connections | |
| • Default: 0 | |
| • Minimum: 0 | |
| Maximum number of sessions dedicated to pipe transactions. | |
| pipe_timeout | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.000 | |
| Idle timeout for PIPE sessions. If nothing have been received in either | |
| direction for this many seconds, the session is closed. | |
| pool_req | |
| • Default: 10,100,10 | |
| Parameters for per worker pool request memory pool. | |
| The three numbers are: | |
| min_pool | |
| minimum size of free pool. | |
| max_pool | |
| maximum size of free pool. | |
| max_age | |
| max age of free element. | |
| pool_sess | |
| • Default: 10,100,10 | |
| Parameters for per worker pool session memory pool. | |
| The three numbers are: | |
| min_pool | |
| minimum size of free pool. | |
| max_pool | |
| maximum size of free pool. | |
| max_age | |
| max age of free element. | |
| pool_vbo | |
| • Default: 10,100,10 | |
| Parameters for backend object fetch memory pool. | |
| The three numbers are: | |
| min_pool | |
| minimum size of free pool. | |
| max_pool | |
| maximum size of free pool. | |
| max_age | |
| max age of free element. | |
| prefer_ipv6 | |
| • Units: bool | |
| • Default: off | |
| Prefer IPv6 address when connecting to backends which have both IPv4 | |
| and IPv6 addresses. | |
| rush_exponent | |
| • Units: requests per request | |
| • Default: 3 | |
| • Minimum: 2 | |
| • Flags: experimental | |
| How many parked request we start for each completed request on the | |
| object. NB: Even with the implict delay of delivery, this parameter | |
| controls an exponential increase in number of worker threads. | |
| send_timeout | |
| • Units: seconds | |
| • Default: 600.000 | |
| • Minimum: 0.000 | |
| • Flags: delayed | |
| Total timeout for ordinary HTTP1 responses. Does not apply to some | |
| internally generated errors and pipe mode. | |
| When 'idle_send_timeout' is hit while sending an HTTP1 response, the | |
| timeout is extended unless the total time already taken for sending the | |
| response in its entirety exceeds this many seconds. | |
| When this timeout is hit, the session is closed | |
| shortlived | |
| • Units: seconds | |
| • Default: 10.000 | |
| • Minimum: 0.000 | |
| Objects created with (ttl+grace+keep) shorter than this are always put | |
| in transient storage. | |
| sigsegv_handler | |
| • Units: bool | |
| • Default: on | |
| • Flags: must_restart | |
| Install a signal handler which tries to dump debug information on | |
| segmentation faults, bus errors and abort signals. | |
| syslog_cli_traffic | |
| • Units: bool | |
| • Default: on | |
| Log all CLI traffic to syslog(LOG_INFO). | |
| tcp_fastopen | |
| NB: This parameter depends on a feature which is not available on all | |
| platforms. | |
| • Units: bool | |
| • Default: off | |
| Enable TCP Fast Open extension. | |
| tcp_keepalive_intvl | |
| NB: This parameter depends on a feature which is not available on all | |
| platforms. | |
| • Units: seconds | |
| • Default: platform dependent | |
| • Minimum: 1 | |
| • Maximum: 100 | |
| The number of seconds between TCP keep-alive probes. Ignored for Unix | |
| domain sockets. | |
| tcp_keepalive_probes | |
| NB: This parameter depends on a feature which is not available on all | |
| platforms. | |
| • Units: probes | |
| • Default: platform dependent | |
| • Minimum: 1 | |
| • Maximum: 100 | |
| The maximum number of TCP keep-alive probes to send before giving up | |
| and killing the connection if no response is obtained from the other | |
| end. Ignored for Unix domain sockets. | |
| tcp_keepalive_time | |
| NB: This parameter depends on a feature which is not available on all | |
| platforms. | |
| • Units: seconds | |
| • Default: platform dependent | |
| • Minimum: 1 | |
| • Maximum: 7200 | |
| The number of seconds a connection needs to be idle before TCP begins | |
| sending out keep-alive probes. Ignored for Unix domain sockets. | |
| thread_pool_add_delay | |
| • Units: seconds | |
| • Default: 0.000 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| Wait at least this long after creating a thread. | |
| Some (buggy) systems may need a short (sub-second) delay between | |
| creating threads. Set this to a few milliseconds if you see the | |
| 'threads_failed' counter grow too much. | |
| Setting this too high results in insufficient worker threads. | |
| thread_pool_destroy_delay | |
| • Units: seconds | |
| • Default: 1.000 | |
| • Minimum: 0.010 | |
| • Flags: delayed, experimental | |
| Wait this long after destroying a thread. | |
| This controls the decay of thread pools when idle(-ish). | |
| thread_pool_fail_delay | |
| • Units: seconds | |
| • Default: 0.200 | |
| • Minimum: 0.010 | |
| • Flags: experimental | |
| Wait at least this long after a failed thread creation before trying to | |
| create another thread. | |
| Failure to create a worker thread is often a sign that the end is | |
| near, because the process is running out of some resource. This delay | |
| tries to not rush the end on needlessly. | |
| If thread creation failures are a problem, check that thread_pool_max | |
| is not too high. | |
| It may also help to increase thread_pool_timeout and thread_pool_min, | |
| to reduce the rate at which treads are destroyed and later recreated. | |
| thread_pool_max | |
| • Units: threads | |
| • Default: 5000 | |
| • Minimum: thread_pool_min | |
| • Flags: delayed | |
| The maximum number of worker threads in each pool. | |
| Do not set this higher than you have to, since excess worker threads | |
| soak up RAM and CPU and generally just get in the way of getting work | |
| done. | |
| thread_pool_min | |
| • Units: threads | |
| • Default: 100 | |
| • Minimum: 5 | |
| • Maximum: thread_pool_max | |
| • Flags: delayed | |
| The minimum number of worker threads in each pool. | |
| Increasing this may help ramp up faster from low load situations or | |
| when threads have expired. | |
| Technical minimum is 5 threads, but this parameter is strongly | |
| recommended to be at least 10 | |
| thread_pool_reserve | |
| • Units: threads | |
| • Default: 0 (auto-tune: 5% of thread_pool_min) | |
| • Maximum: 95% of thread_pool_min | |
| • Flags: delayed | |
| The number of worker threads reserved for vital tasks in each pool. | |
| Tasks may require other tasks to complete (for example, client requests | |
| may require backend requests, http2 sessions require streams, which | |
| require requests). This reserve is to ensure that lower priority tasks | |
| do not prevent higher priority tasks from running even under high load. | |
| The effective value is at least 5 (the number of internal priority | |
| classes), irrespective of this parameter. | |
| thread_pool_stack | |
| • Units: bytes | |
| • Default: 80k | |
| • Minimum: sysconf(_SC_THREAD_STACK_MIN) | |
| • Flags: delayed | |
| Worker thread stack size. This will likely be rounded up to a multiple | |
| of 4k (or whatever the page_size might be) by the kernel. | |
| The required stack size is primarily driven by the depth of the | |
| call-tree. The most common relevant determining factors in varnish core | |
| code are GZIP (un)compression, ESI processing and regular expression | |
| matches. VMODs may also require significant amounts of additional | |
| stack. The nesting depth of VCL subs is another factor, although | |
| typically not predominant. | |
| The stack size is per thread, so the maximum total memory required for | |
| worker thread stacks is in the order of size = thread_pools x | |
| thread_pool_max x thread_pool_stack. | |
| Thus, in particular for setups with many threads, keeping the stack | |
| size at a minimum helps reduce the amount of memory required by | |
| Varnish. | |
| On the other hand, thread_pool_stack must be large enough under all | |
| circumstances, otherwise varnish will crash due to a stack overflow. | |
| Usually, a stack overflow manifests itself as a segmentation fault (aka | |
| segfault / SIGSEGV) with the faulting address being near the stack | |
| pointer (sp). | |
| Unless stack usage can be reduced, thread_pool_stack must be increased | |
| when a stack overflow occurs. Setting it in 150%-200% increments is | |
| recommended until stack overflows cease to occur. | |
| thread_pool_timeout | |
| • Units: seconds | |
| • Default: 300.000 | |
| • Minimum: 10.000 | |
| • Flags: delayed, experimental | |
| Thread idle threshold. | |
| Threads in excess of thread_pool_min, which have been idle for at least | |
| this long, will be destroyed. | |
| thread_pool_watchdog | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 0.100 | |
| • Flags: experimental | |
| Thread queue stuck watchdog. | |
| If no queued work have been released for this long, the worker process | |
| panics itself. | |
| thread_pools | |
| • Units: pools | |
| • Default: 2 | |
| • Minimum: 1 | |
| • Maximum: 32 | |
| • Flags: delayed, experimental | |
| Number of worker thread pools. | |
| Increasing the number of worker pools decreases lock contention. Each | |
| worker pool also has a thread accepting new connections, so for very | |
| high rates of incoming new connections on systems with many cores, | |
| increasing the worker pools may be required. | |
| Too many pools waste CPU and RAM resources, and more than one pool for | |
| each CPU is most likely detrimental to performance. | |
| Can be increased on the fly, but decreases require a restart to take | |
| effect, unless the drop_pools experimental debug flag is set. | |
| thread_queue_limit | |
| • Units: requests | |
| • Default: 20 | |
| • Minimum: 0 | |
| • Flags: experimental | |
| Permitted request queue length per thread-pool. | |
| This sets the number of requests we will queue, waiting for an | |
| available thread. Above this limit sessions will be dropped instead of | |
| queued. | |
| thread_stats_rate | |
| • Units: requests | |
| • Default: 10 | |
| • Minimum: 0 | |
| • Flags: experimental | |
| Worker threads accumulate statistics, and dump these into the global | |
| stats counters if the lock is free when they finish a job | |
| (request/fetch etc.) This parameters defines the maximum number of | |
| jobs a worker thread may handle, before it is forced to dump its | |
| accumulated stats into the global counters. | |
| timeout_idle | |
| • Units: seconds | |
| • Default: 5.000 | |
| • Minimum: 0.000 | |
| Idle timeout for client connections. | |
| A connection is considered idle until we have received the full request | |
| headers. | |
| This parameter is particularly relevant for HTTP1 keepalive | |
| connections which are closed unless the next request is received before | |
| this timeout is reached. | |
| timeout_linger | |
| • Units: seconds | |
| • Default: 0.050 | |
| • Minimum: 0.000 | |
| • Flags: experimental | |
| How long the worker thread lingers on an idle session before handing it | |
| over to the waiter. When sessions are reused, as much as half of all | |
| reuses happen within the first 100 msec of the previous request | |
| completing. Setting this too high results in worker threads not doing | |
| anything for their keep, setting it too low just means that more | |
| sessions take a detour around the waiter. | |
| transit_buffer | |
| • Units: bytes | |
| • Default: 0b | |
| • Minimum: 0b | |
| The number of bytes which Varnish buffers for uncacheable backend | |
| streaming fetches - in other words, how many bytes Varnish reads from | |
| the backend ahead of what has been sent to the client. A zero value | |
| means no limit, the object is fetched as fast as possible. | |
| When dealing with slow clients, setting this parameter to non-zero can | |
| prevent large uncacheable objects from being stored in full when the | |
| intent is to simply stream them to the client. As a result, a slow | |
| client transaction holds onto a backend connection until the end of the | |
| delivery. | |
| This parameter is the default to the VCL variable | |
| beresp.transit_buffer, which can be used to control the transit buffer | |
| per backend request. | |
| vary_notice | |
| • Units: variants | |
| • Default: 10 | |
| • Minimum: 1 | |
| How many variants need to be evaluated to log a Notice that there might | |
| be too many variants. | |
| vcc_allow_inline_c | |
| Deprecated alias for the vcc_feature parameter. | |
| vcc_err_unref | |
| Deprecated alias for the vcc_feature parameter. | |
| vcc_feature | |
| • Default: +err_unref,+unsafe_path | |
| Enable/Disable various VCC behaviors. | |
| default | |
| Set default value | |
| none Disable all behaviors. | |
| Use +/- prefix to enable/disable individual behavior: | |
| err_unref | |
| Unreferenced VCL objects result in error. | |
| allow_inline_c | |
| Allow inline C code in VCL. | |
| unsafe_path | |
| Allow '/' in vmod & include paths. Allow 'import ... from | |
| ...'. | |
| vcc_unsafe_path | |
| Deprecated alias for the vcc_feature parameter. | |
| vcl_cooldown | |
| • Units: seconds | |
| • Default: 600.000 | |
| • Minimum: 1.000 | |
| How long a VCL is kept warm after being replaced as the active VCL | |
| (granularity approximately 30 seconds). | |
| vcl_path | |
| NB: The actual default value for this parameter depends on the Varnish | |
| build environment and options. | |
| • Default: ${sysconfdir}/varnish:${datadir}/varnish/vcl | |
| Directory (or colon separated list of directories) from which relative | |
| VCL filenames (vcl.load and include) are to be found. By default | |
| Varnish searches VCL files in both the system configuration and shared | |
| data directories to allow packages to drop their VCL files in a | |
| standard location where relative includes would work. | |
| vmod_path | |
| NB: The actual default value for this parameter depends on the Varnish | |
| build environment and options. | |
| • Default: ${libdir}/varnish/vmods | |
| Directory (or colon separated list of directories) where VMODs are to | |
| be found. | |
| vsl_buffer | |
| • Units: bytes | |
| • Default: 16k | |
| • Minimum: vsl_reclen + 12 bytes | |
| Bytes of (req-/backend-)workspace dedicated to buffering VSL records. | |
| When this parameter is adjusted, most likely workspace_client and | |
| workspace_backend will have to be adjusted by the same amount. | |
| Setting this too high costs memory, setting it too low will cause more | |
| VSL flushes and likely increase lock-contention on the VSL mutex. | |
| vsl_mask | |
| • Default: | |
| -Debug,-ObjProtocol,-ObjStatus,-ObjReason,-ObjHeader,-VCL_trace,-ExpKill,-WorkThread,-Hash,-VfpAcct,-H2RxHdr,-H2RxBody,-H2TxHdr,-H2TxBody,-VdpAcct | |
| Mask individual VSL messages from being logged. | |
| default | |
| Set default value | |
| Use +/- prefix in front of VSL tag name to unmask/mask individual VSL | |
| messages. | |
| vsl_reclen | |
| • Units: bytes | |
| • Default: 255b | |
| • Minimum: 16b | |
| • Maximum: vsl_buffer - 12 bytes | |
| Maximum number of bytes in SHM log record. | |
| vsl_space | |
| • Units: bytes | |
| • Default: 80M | |
| • Minimum: 1M | |
| • Maximum: 4G | |
| • Flags: must_restart | |
| The amount of space to allocate for the VSL fifo buffer in the VSM | |
| memory segment. If you make this too small, varnish{ncsa|log} etc will | |
| not be able to keep up. Making it too large just costs memory | |
| resources. | |
| vsm_free_cooldown | |
| • Units: seconds | |
| • Default: 60.000 | |
| • Minimum: 10.000 | |
| • Maximum: 600.000 | |
| How long VSM memory is kept warm after a deallocation (granularity | |
| approximately 2 seconds). | |
| workspace_backend | |
| • Units: bytes | |
| • Default: 96k | |
| • Minimum: 1k | |
| • Flags: delayed | |
| Bytes of HTTP protocol workspace for backend HTTP req/resp. If larger | |
| than 4k, use a multiple of 4k for VM efficiency. | |
| workspace_client | |
| • Units: bytes | |
| • Default: 96k | |
| • Minimum: 9k | |
| • Flags: delayed | |
| Bytes of HTTP protocol workspace for clients HTTP req/resp. Use a | |
| multiple of 4k for VM efficiency. For HTTP/2 compliance this must be | |
| at least 20k, in order to receive fullsize (=16k) frames from the | |
| client. That usually happens only in POST/PUT bodies. For other | |
| traffic-patterns smaller values work just fine. | |
| workspace_session | |
| • Units: bytes | |
| • Default: 0.75k | |
| • Minimum: 384b | |
| • Flags: delayed | |
| Allocation size for session structure and workspace. The workspace | |
| is primarily used for TCP connection addresses. If larger than 4k, use | |
| a multiple of 4k for VM efficiency. | |
| workspace_thread | |
| • Units: bytes | |
| • Default: 2k | |
| • Minimum: 0.25k | |
| • Maximum: 8k | |
| • Flags: delayed | |
| Bytes of auxiliary workspace per thread. This workspace is used for | |
| certain temporary data structures during the operation of a worker | |
| thread. One use is for the IO-vectors used during delivery. Setting | |
| this parameter too low may increase the number of writev() syscalls, | |
| setting it too high just wastes space. ~0.1k + UIO_MAXIOV * | |
| sizeof(struct iovec) (typically = ~16k for 64bit) is considered the | |
| maximum sensible value under any known circumstances (excluding exotic | |
| vmod use). | |
| EXIT CODES | |
| Varnish and bundled tools will, in most cases, exit with one of the | |
| following codes | |
| • 0 OK | |
| • 1 Some error which could be system-dependent and/or transient | |
| • 2 Serious configuration / parameter error - retrying with the same | |
| configuration / parameters is most likely useless | |
| The varnishd master process may also OR its exit code | |
| • with 0x20 when the varnishd child process died, | |
| • with 0x40 when the varnishd child process was terminated by a signal | |
| and | |
| • with 0x80 when a core was dumped. | |
| SEE ALSO | |
| • varnishlog(1) | |
| • varnishhist(1) | |
| • varnishncsa(1) | |
| • varnishstat(1) | |
| • varnishtop(1) | |
| • varnish-cli(7) | |
| • vcl(7) | |
| HISTORY | |
| The varnishd daemon was developed by Poul-Henning Kamp in cooperation | |
| with Verdens Gang AS and Varnish Software. | |
| This manual page was written by Dag-Erling Smørgrav with updates by | |
| Stig Sandbeck Mathisen <ssm@debian.org>, Nils Goroll and others. | |
| COPYRIGHT | |
| This document is licensed under the same licence as Varnish itself. See | |
| LICENCE for details. | |
| • Copyright (c) 2007-2015 Varnish Software AS | |
| VARNISHD(1) |
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