Matouš Jan Fialka
2015-03-31
Varnish Cache v4.0.2
varnish_cache.2015.3.31.1
sub vcl_backend_response {
if(beresp.status == 404) {
set beresp.ttl = 30s;
}
}sub vcl_backend_response {
if(beresp.status == 404) {
set beresp.ttl = 0s;
set beresp.uncacheable = false;
}
}Matouš Jan Fialka
2015-01-12
Varnish Cache v4.0.2
varnish_cache.2015.1.12.1
| subroutine | scope | deliver | fetch | restart | hash | pass | pipe | synth | purge | lookup | abandon | retry | ok | fail |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| vcl_deliver | client | ✓ | ✓ | ✓ | ||||||||||
| vcl_fini | vcl.discard | ✓ | ||||||||||||
| vcl_hash | client | ✓ | ||||||||||||
| vcl_hit | client | ✓ | ✓ | ✓ | ✓ | ✓ | ||||||||
| vcl_init | vcl.load | ✓ | ✓ | |||||||||||
| vcl_miss | client | ✓ | ✓ | ✓ | ✓ | |||||||||
| vcl_pass | client | ✓ | ✓ | ✓ | ||||||||||
| vcl_pipe | client | ✓ | ✓ | |||||||||||
| vcl_purge | client | ✓ | ✓ | |||||||||||
| vcl_recv | client | ✓ | ✓ | ✓ | ✓ | ✓ | ||||||||
| vcl_synth | client | ✓ | ✓ | |||||||||||
| vcl_backend_error | backend | ✓ | ✓ | |||||||||||
| vcl_backend_fetch | backend | ✓ | ✓ | |||||||||||
| vcl_backend_response | backend | ✓ | ✓ | ✓ |
Matouš Jan Fialka
2015-01-12
Varnish Cache v4.0.2
varnish_cache.2015.1.12.2
acceptor_sleep_decay
- Value is: 0.9 (default)
- Default is: 0.9
- Minimum is: 0
- Maximum is: 1
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 succesfull accept. (ie: 0.9 = reduce by 10%)
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
acceptor_sleep_incr
- Value is: 0.001 [s] (default)
- Default is: 0.001
- Minimum is: 0.000
- Maximum is: 1.000
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
acceptor_sleep_max
- Value is: 0.050 [s] (default)
- Default is: 0.050
- Minimum is: 0.000
- Maximum is: 10.000
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
auto_restart
- Value is: on [bool] (default)
- Default is: on
Restart child process automatically if it dies.
ban_dups
- Value is: on [bool] (default)
- Default is: on
Elimited older identical bans when new bans are created. This
test is CPU intensive and scales with the number and complexity
of active (non-Gone) bans. If identical bans are frequent, the
amount of CPU needed to actually test the bans will be
similarly reduced.
ban_lurker_age
- Value is: 60.000 [s] (default)
- Default is: 60.000
- Minimum is: 0.000
The ban lurker does not process bans until they are this old.
Right when a ban is added, the most frequently hit objects will
get tested against it as part of object lookup. This parameter
prevents the ban-lurker from kicking in, until the rush is
over.
ban_lurker_batch
- Value is: 1000 (default)
- Default is: 1000
- Minimum is: 1
How many objects the ban lurker examines before taking a
ban_lurker_sleep. Use this to pace the ban lurker so it does
not eat too much CPU.
ban_lurker_sleep
- Value is: 0.010 [s] (default)
- Default is: 0.010
- Minimum is: 0.000
The ban lurker thread sleeps between work batches, in order to
not monopolize CPU power. When nothing is done, it sleeps a
fraction of a second before looking for new work to do.
A value of zero disables the ban lurker.
between_bytes_timeout
- Value is: 60.000 [s] (default)
- Default is: 60.000
- Minimum is: 0.000
Default timeout between bytes when receiving data from backend.
We only wait for this many seconds between bytes before giving
up. A value of 0 means it will never time out. VCL can override
this default value for each backend request and backend
request. This parameter does not apply to pipe.
busyobj_worker_cache
- Value is: off [bool] (default)
- Default is: off
Cache free busyobj per worker thread. Disable this if you have
very high hitrates and want to save the memory of one busyobj
per worker thread.
cc_command
- Value is: "exec gcc -std=gnu99 -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic -Wall -Werror -Wno-error=unused-result -pthread -fpic -shared -Wl,-x -o %o %s" (default)
- Default is: "exec gcc -std=gnu99 -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic -Wall -Werror -Wno-error=unused-result -pthread -fpic -shared -Wl,-x -o %o %s"
Command used for compiling the C source code to a dlopen(3)
loadable object. Any occurrence of %s in the string will be
replaced with the source file name, and %o will be replaced
with the output file name.
NB: This parameter will not take any effect until the VCL
programs have been reloaded.
cli_buffer
- Value is: 8k [bytes] (default)
- Default is: 8k
- Minimum is: 4k
Size of buffer for CLI command input.
You may need to increase this if you have big VCL files and use
the vcl.inline CLI command.
NB: Must be specified with -p to have effect.
cli_limit
- Value is: 48k [bytes] (default)
- Default is: 48k
- Minimum is: 128b
- Maximum is: 99999999b
Maximum size of CLI response. If the response exceeds this
limit, the reponse code will be 201 instead of 200 and the last
line will indicate the truncation.
cli_timeout
- Value is: 60.000 [seconds] (default)
- Default is: 60.000
- Minimum is: 0.000
Timeout for the childs replies to CLI requests from the
mgt_param.
clock_skew
- Value is: 10 [s] (default)
- Default is: 10
- Minimum is: 0
How much clockskew we are willing to accept between the backend
and our own clock.
connect_timeout
- Value is: 3.500 [s] (default)
- Default is: 3.500
- Minimum is: 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
- Value is: 180.000 [s] (default)
- Default is: 180.000
- Minimum is: 60.000
- Maximum is: 254.000
How long time the critbit hasher keeps deleted objheads on the
cooloff list.
NB: Do not change this parameter, unless a developer tell you
to do so.
debug
- Value is: none (default)
- Default is: 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
waiter VSL Waiter internals
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
default_grace
- Value is: 10.000 [seconds] (default)
- Default is: 10.000
- Minimum is: 0.000
Default grace period. We will deliver an object this long
after it has expired, provided another thread is attempting to
get a new copy.
NB: This parameter is evaluated only when objects are
created.To change it for all objects, restart or ban
everything.
default_keep
- Value is: 0.000 [seconds] (default)
- Default is: 0.000
- Minimum is: 0.000
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.
NB: This parameter is evaluated only when objects are
created.To change it for all objects, restart or ban
everything.
default_ttl
- Value is: 1200.000 [seconds]
- Default is: 120.000
- Minimum is: 0.000
The TTL assigned to objects if neither the backend nor the VCL
code assigns one.
NB: This parameter is evaluated only when objects are
created.To change it for all objects, restart or ban
everything.
feature
- Value is: none (default)
- Default is: none
Enable/Disable various minor features.
none Disable all features.
Use +/- prefix to enable/disable individual feature:
short_panic Short panic message.
wait_silo Wait for persistent silo.
no_coredump No coredumps.
esi_ignore_https Treat HTTPS as HTTP in
ESI:includes
esi_disable_xml_check Don't check of body looks like
XML
esi_ignore_other_elements Ignore non-esi XML-elements
esi_remove_bom Remove UTF-8 BOM
fetch_chunksize
- Value is: 32k [bytes]
- Default is: 128k
- Minimum is: 4k
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
fetch_maxchunksize
- Value is: 0.25G [bytes] (default)
- Default is: 0.25G
- Minimum is: 64k
The maximum chunksize we attempt to allocate from storage.
Making this too large may cause delays and storage
fragmentation.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
first_byte_timeout
- Value is: 60.000 [s] (default)
- Default is: 60.000
- Minimum is: 0.000
Default timeout for receiving first byte from backend. We only
wait for this many seconds for the first byte before giving up.
A value of 0 means it will never time out. VCL can override
this default value for each backend and backend request. This
parameter does not apply to pipe.
group
- Value is: varnish (998)
- Default is: GID 0
The unprivileged group to run as.
NB: This parameter will not take any effect until the child
process has been restarted.
NB: This parameter only works if varnishd is run as root.
group_cc
- Value is: <not set> (default)
- Default is: <not set>
On some systems the C-compiler is restricted so not everybody
can run it. This parameter makes it possible to add an extra
group to the sandbox process which runs the cc_command, in
order to gain access to such a restricted C-compiler.
NB: This parameter only works if varnishd is run as root.
gzip_buffer
- Value is: 32k [bytes] (default)
- Default is: 32k
- Minimum is: 2k
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
gzip_level
- Value is: 6 (default)
- Default is: 6
- Minimum is: 0
- Maximum is: 9
Gzip compression level: 0=debug, 1=fast, 9=best
gzip_memlevel
- Value is: 8 (default)
- Default is: 8
- Minimum is: 1
- Maximum is: 9
Gzip memory level 1=slow/least, 9=fast/most compression.
Memory impact is 1=1k, 2=2k, ... 9=256k.
http_gzip_support
- Value is: on [bool] (default)
- Default is: 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.
http_max_hdr
- Value is: 64 [header lines] (default)
- Default is: 64
- Minimum is: 32
- Maximum is: 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
- Value is: on [bool] (default)
- Default is: on
Enable support for HTTP Range headers.
http_req_hdr_len
- Value is: 8k [bytes] (default)
- Default is: 8k
- Minimum is: 40b
Maximum length of any HTTP client request header we will allow.
The limit is inclusive its continuation lines.
http_req_size
- Value is: 32k [bytes] (default)
- Default is: 32k
- Minimum is: 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
- Value is: 8k [bytes] (default)
- Default is: 8k
- Minimum is: 40b
Maximum length of any HTTP backend response header we will
allow. The limit is inclusive its continuation lines.
http_resp_size
- Value is: 32k [bytes] (default)
- Default is: 32k
- Minimum is: 0.25k
Maximum number of bytes of HTTP backend resonse 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 worker
workspace (param: thread_pool_workspace) and this parameter
limits how much of that the request is allowed to take up.
idle_send_timeout
- Value is: 60.000 [seconds] (default)
- Default is: 60.000
- Minimum is: 0.000
Time to wait with no data sent. If no data has been transmitted
in this many
seconds the session is closed.
See setsockopt(2) under SO_SNDTIMEO for more information.
NB: This parameter may take quite some time to take (full)
effect.
listen_address
- Value is: varnish.bec1.data:6081
- Default is: :80
Whitespace separated list of network endpoints where Varnish
will accept requests.
Possible formats: host, host:port, :port
NB: This parameter will not take any effect until the child
process has been restarted.
listen_depth
- Value is: 1024 [connections] (default)
- Default is: 1024
- Minimum is: 0
Listen queue depth.
NB: This parameter will not take any effect until the child
process has been restarted.
lru_interval
- Value is: 2.000 [seconds] (default)
- Default is: 2.000
- Minimum is: 0.000
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
max_esi_depth
- Value is: 5 [levels] (default)
- Default is: 5
- Minimum is: 0
Maximum depth of esi:include processing.
max_restarts
- Value is: 4 [restarts] (default)
- Default is: 4
- Minimum is: 0
Upper limit on how many times a request can restart.
Be aware that restarts are likely to cause a hit against the
backend, so don't increase thoughtlessly.
max_retries
- Value is: 4 [retries] (default)
- Default is: 4
- Minimum is: 0
Upper limit on how many times a backend fetch can retry.
nuke_limit
- Value is: 50 [allocations] (default)
- Default is: 50
- Minimum is: 0
Maximum number of objects we attempt to nuke in orderto make
space for a object body.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
pcre_match_limit
- Value is: 10000 (default)
- Default is: 10000
- Minimum is: 1
The limit for the number of internal matching function calls
in a pcre_exec() execution.
pcre_match_limit_recursion
- Value is: 10000 (default)
- Default is: 10000
- Minimum is: 1
The limit for the number of internal matching function
recursions in a pcre_exec() execution.
ping_interval
- Value is: 3 [seconds] (default)
- Default is: 3
- Minimum is: 0
Interval between pings from parent to child.
Zero will disable pinging entirely, which makes it possible to
attach a debugger to the child.
NB: This parameter will not take any effect until the child
process has been restarted.
pipe_timeout
- Value is: 60.000 [seconds] (default)
- Default is: 60.000
- Minimum is: 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
- Value is: 10,100,10 (default)
- Default is: 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
- Value is: 10,100,10 (default)
- Default is: 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_vbc
- Value is: 10,100,10 (default)
- Default is: 10,100,10
Parameters for backend connection 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
- Value is: 10,100,10 (default)
- Default is: 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
- Value is: off [bool] (default)
- Default is: off
Prefer IPv6 address when connecting to backends which have both
IPv4 and IPv6 addresses.
rush_exponent
- Value is: 3 [requests per request] (default)
- Default is: 3
- Minimum is: 2
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
send_timeout
- Value is: 600.000 [seconds] (default)
- Default is: 600.000
- Minimum is: 0.000
Send timeout for client connections. If the HTTP response
hasn't been transmitted in this many
seconds the session is closed.
See setsockopt(2) under SO_SNDTIMEO for more information.
NB: This parameter may take quite some time to take (full)
effect.
session_max
- Value is: 100000 [sessions] (default)
- Default is: 100000
- Minimum is: 1000
Maximum number of sessions we will allocate from one pool
before just dropping connections.
This is mostly an anti-DoS measure, and setting it plenty high
should not hurt, as long as you have the memory for it.
shm_reclen
- Value is: 255b [bytes] (default)
- Default is: 255b
- Minimum is: 16b
- Maximum is: 4084
Old name for vsl_reclen, use that instead.
shortlived
- Value is: 10.000 [s] (default)
- Default is: 10.000
- Minimum is: 0.000
Objects created with (ttl+grace+keep) shorter than this are
always put in transient storage.
sigsegv_handler
- Value is: off [bool] (default)
- Default is: off
Install a signal handler which tries to dump debug information
on segmentation faults.
NB: This parameter will not take any effect until the child
process has been restarted.
syslog_cli_traffic
- Value is: on [bool] (default)
- Default is: on
Log all CLI traffic to syslog(LOG_INFO).
tcp_keepalive_intvl
- Value is: 75.000 [seconds] (default)
- Default is: 75.000
- Minimum is: 1.000
- Maximum is: 100.000
The number of seconds between TCP keep-alive probes.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
tcp_keepalive_probes
- Value is: 9 [probes] (default)
- Default is: 9
- Minimum is: 1
- Maximum is: 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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
tcp_keepalive_time
- Value is: 7200.000 [seconds] (default)
- Default is: 7200.000
- Minimum is: 1.000
- Maximum is: 7200.000
The number of seconds a connection needs to be idle before TCP
begins sending out keep-alive probes.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pool_add_delay
- Value is: 2.000 [seconds]
- Default is: 0.000
- Minimum is: 0.000
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 insuffient worker threads.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pool_destroy_delay
- Value is: 1.000 [seconds] (default)
- Default is: 1.000
- Minimum is: 0.010
Wait this long after destroying a thread.
This controls the decay of thread pools when idle(-ish).
Minimum is 0.01 second.
NB: This parameter may take quite some time to take (full)
effect.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pool_fail_delay
- Value is: 0.200 [seconds] (default)
- Default is: 0.200
- Minimum is: 0.010
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pool_max
- Value is: 4000 [threads]
- Default is: 5000
- Minimum is: 2000
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.
Minimum is 10 threads.
NB: This parameter may take quite some time to take (full)
effect.
thread_pool_min
- Value is: 2000 [threads]
- Default is: 100
- Maximum is: 4000
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.
Minimum is 10 threads.
NB: This parameter may take quite some time to take (full)
effect.
thread_pool_stack
- Value is: 48k [bytes] (default)
- Default is: 48k
- Minimum is: 16k
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pool_timeout
- Value is: 300.000 [seconds] (default)
- Default is: 300.000
- Minimum is: 10.000
Thread idle threshold.
Threads in excess of thread_pool_min, which have been idle for
at least this long, will be destroyed.
Minimum is 10 seconds.
NB: This parameter may take quite some time to take (full)
effect.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_pools
- Value is: 4 [pools]
- Default is: 2
- Minimum is: 1
Number of worker thread pools.
Increasing number of worker pools decreases lock contention.
Too many pools waste CPU and RAM resources, and more than one
pool for each CPU is probably detrimal to performance.
Can be increased on the fly, but decreases require a restart to
take effect.
NB: This parameter may take quite some time to take (full)
effect.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_queue_limit
- Value is: 20 (default)
- Default is: 20
- Minimum is: 0
Permitted 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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
thread_stats_rate
- Value is: 10 [requests] (default)
- Default is: 10
- Minimum is: 0
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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
timeout_idle
- Value is: 5.000 [seconds] (default)
- Default is: 5.000
- Minimum is: 0.000
Idle timeout for client connections.
A connection is considered idle, until we receive a
non-white-space character on it.
timeout_linger
- Value is: 0.050 [seconds] (default)
- Default is: 0.050
- Minimum is: 0.000
How long time the workerthread 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.
NB: We do not know yet if it is a good idea to change this
parameter, or if the default value is even sensible. Caution
is advised, and feedback is most welcome.
timeout_req
- Value is: 2.000 [seconds] (default)
- Default is: 2.000
- Minimum is: 0.000
Max time to receive clients request header, measured from first
non-white-space character to double CRNL.
user
- Value is: varnish (999)
- Default is: nobody (99)
The unprivileged user to run as.
NB: This parameter will not take any effect until the child
process has been restarted.
NB: This parameter only works if varnishd is run as root.
vcc_allow_inline_c
- Value is: off [bool] (default)
- Default is: off
Allow inline C code in VCL.
vcc_err_unref
- Value is: on [bool] (default)
- Default is: on
Unreferenced VCL objects result in error.
vcc_unsafe_path
- Value is: on [bool] (default)
- Default is: on
Allow '/' in vmod & include paths.
Allow 'import ... from ...'.
vcl_dir
- Value is: /etc/varnish (default)
- Default is: /etc/varnish
Directory from which relative VCL filenames (vcl.load and
include) are opened.
vmod_dir
- Value is: /usr/lib64/varnish/vmods (default)
- Default is: /usr/lib64/varnish/vmods
Directory where VCL modules are to be found.
vsl_buffer
- Value is: 4k [bytes] (default)
- Default is: 4k
- Minimum is: 267
Bytes of (req-/backend-)workspace dedicated to buffering VSL
records.
Setting this too high costs memory, setting it too low will
cause more VSL flushes and likely increase lock-contention on
the VSL mutex.
The minimum tracks the vsl_reclen parameter + 12 bytes.
vsl_mask
- Value is: -VCL_trace,-WorkThread,-Hash (default)
- Default is: -VCL_trace,-WorkThread,-Hash
Mask individual VSL messages from being logged.
default Set default value
Use +/- prefixe in front of VSL tag name, to mask/unmask
individual VSL messages.
vsl_reclen
- Value is: 255b [bytes] (default)
- Default is: 255b
- Minimum is: 16b
- Maximum is: 4084
Maximum number of bytes in SHM log record.
The maximum tracks the vsl_buffer parameter - 12 bytes.
vsl_space
- Value is: 80M [bytes] (default)
- Default is: 80M
- Minimum is: 1M
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.
NB: This parameter will not take any effect until the child
process has been restarted.
vsm_space
- Value is: 1M [bytes] (default)
- Default is: 1M
- Minimum is: 1M
The amount of space to allocate for stats counters in the VSM
memory segment. If you make this too small, some counters will
be invisible. Making it too large just costs memory resources.
NB: This parameter will not take any effect until the child
process has been restarted.
waiter
- Value is: epoll (possible values: epoll, poll) (default)
- Default is: epoll (possible values: epoll, poll)
Select the waiter kernel interface.
NB: This parameter will not take any effect until the child
process has been restarted.
NB: Do not change this parameter, unless a developer tell you
to do so.
workspace_backend
- Value is: 64k [bytes] (default)
- Default is: 64k
- Minimum is: 1k
Bytes of HTTP protocol workspace for backend HTTP req/resp. If
larger than 4k, use a multiple of 4k for VM efficiency.
NB: This parameter may take quite some time to take (full)
effect.
workspace_client
- Value is: 64k [bytes] (default)
- Default is: 64k
- Minimum is: 9k
Bytes of HTTP protocol workspace for clients HTTP req/resp. If
larger than 4k, use a multiple of 4k for VM efficiency.
NB: This parameter may take quite some time to take (full)
effect.
workspace_session
- Value is: 384b [bytes] (default)
- Default is: 384b
- Minimum is: 0.25k
Bytes of workspace for session and TCP connection addresses.
If larger than 4k, use a multiple of 4k for VM efficiency.
NB: This parameter may take quite some time to take (full)
effect.
workspace_thread
- Value is: 2k [bytes] (default)
- Default is: 2k
- Minimum is: 0.25k
- Maximum is: 8k
Bytes of auxillary 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 for writing requests and
responses to sockets, having too little space will result in
more writev(2) system calls, having too much just wastes the
space.
NB: This parameter may take quite some time to take (full)
effect.