@@ -311,533 +311,529 @@ Be aware that on 32 bit systems, certain default values, such as sess_workspace
(=64k) are reduced relative to the values listed here, in order to conserve VM space.
acceptor_sleep_decay
Default: 0.900
Flags: experimental
- Default: 0.900
- 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 succesfull accept. (ie: 0.9 = reduce
by 10%)
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%)
acceptor_sleep_incr
Units: s
Default: 0.001
Flags: experimental
- Units: s
- Default: 0.001
- 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.
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: s
Default: 0.050
Flags: experimental
- Units: s
- Default: 0.050
- 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.
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
- Units: bool
- Default: on
Restart child process automatically if it dies.
Restart child process automatically if it dies.
ban_dups
- Units: bool
- Default: on
Detect and eliminate duplicate bans.
ban_lurker_sleep
Units: s
Default: 0.0
- Units: s
- Default: 0.1
How long time does the ban lurker thread sleeps between successfull attempts to push the last item up the
purge list. It always sleeps a second when nothing can be done.
A value of zero disables the ban lurker.
How long time does the ban lurker thread sleeps between successful attempts to push the last item up the ban list. It always sleeps a second when nothing can be done.
A value of zero disables the ban lurker.
between_bytes_timeout
Units: s
Default: 60
- Units: s
- Default: 60
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.
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.
cache_vbe_conns
Units: bool
Default: off
Flags: experimental
cache_vbcs
- Units: bool
- Default: off
- Flags: experimental
Cache vbe_conn's or rely on malloc, that's the question.
Cache vbc's or rely on malloc, that's the question.
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.
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.
cli_buffer
Units: bytes
Default: 8192
- Units: bytes
- Default: 8192
Size of buffer for CLI 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.
Size of buffer for CLI 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_timeout
Units: seconds
Default: 10
- Units: seconds
- Default: 10
Timeout for the childs replies to CLI requests from the master.
Timeout for the childs replies to CLI requests from the master.
clock_skew
Units: s
Default: 10
- Units: s
- Default: 10
How much clockskew we are willing to accept between the backend and our own clock.
How much clockskew we are willing to accept between the backend and our own clock.
connect_timeout
Units: s
Default: 0.4
- Units: s
- Default: 0.4
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: s
- Default: 180.0
- Flags: experimental
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.
How long time the critbit hasher keeps deleted objheads on the cooloff list.
default_grace
Default: 10seconds
Flags: delayed
- Units: seconds
- Default: 10
- Flags: delayed
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 grace period. We will deliver an object this long after it has expired, provided another thread is attempting to get a new copy.
Objects already cached will not be affected by changes made until they are fetched from the backend again.
default_ttl
Units: seconds
Default: 120
- Units: seconds
- Default: 120
The TTL assigned to objects if neither the backend nor the VCL code assigns one.
Objects already cached will not be affected by changes made until they are fetched from the backend again.
To force an immediate effect at the expense of a total flush of the cache use "purge.url ."
The TTL assigned to objects if neither the backend nor the VCL code assigns one.
Objects already cached will not be affected by changes made until they are fetched from the backend again.
To force an immediate effect at the expense of a total flush of the cache use "ban.url ."
diag_bitmap
Units: bitmap
Default: 0
Bitmap controlling diagnostics code::
0x00000001 - CNT_Session states.
0x00000002 - workspace debugging.
0x00000004 - kqueue debugging.
0x00000008 - mutex logging.
0x00000010 - mutex contests.
0x00000020 - waiting list.
0x00000040 - object workspace.
0x00001000 - do not core-dump child process.
0x00002000 - only short panic message.
0x00004000 - panic to stderr.
0x00008000 - panic to abort2().
0x00010000 - synchronize shmlog.
0x00020000 - synchronous start of persistence.
0x80000000 - do edge-detection on digest.
Use 0x notation and do the bitor in your head :-)
- Units: bitmap
- Default: 0
Bitmap controlling diagnostics code::
0x00000001 - CNT_Session states.
0x00000002 - workspace debugging.
0x00000004 - kqueue debugging.
0x00000008 - mutex logging.
0x00000010 - mutex contests.
0x00000020 - waiting list.
0x00000040 - object workspace.
0x00001000 - do not core-dump child process.
0x00002000 - only short panic message.
0x00004000 - panic to stderr.
0x00010000 - synchronize shmlog.
0x00020000 - synchronous start of persistence.
0x00040000 - release VCL early.
0x80000000 - do edge-detection on digest.
Use 0x notation and do the bitor in your head :-)
err_ttl
Units: seconds
Default: 0
- Units: seconds
- Default: 0
The TTL assigned to the synthesized error pages
The TTL assigned to the synthesized error pages
esi_syntax
Units: bitmap
Default: 0
Bitmap controlling ESI parsing code::
- Units: bitmap
- Default: 0
0x00000001 - Don't check if it looks like XML
0x00000002 - Ignore non-esi elements
0x00000004 - Emit parsing debug records
Bitmap controlling ESI parsing code::
Use 0x notation and do the bitor in your head :-)
0x00000001 - Don't check if it looks like XML
0x00000002 - Ignore non-esi elements
0x00000004 - Emit parsing debug records
0x00000008 - Force-split parser input (debugging)
Use 0x notation and do the bitor in your head :-)
expiry_sleep
- Units: seconds
- Default: 1
How long the expiry thread sleeps when there is nothing for it to do. Reduce if your expiry thread gets behind.
fetch_chunksize
Units: kilobytes
Default: 128
Flags: experimental
- Units: kilobytes
- Default: 128
- 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.
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.
first_byte_timeout
Units: s
Default: 60
- Units: s
- Default: 60
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.
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
Default: .....
Flags: must_restart
- Default: magic
- Flags: must_restart
The unprivileged group to run as.
The unprivileged group to run as.
gzip_level
Default: 6
- Default: 6
Gzip compression level ranging from 1 (the fastest) to 9 (the
smallest possible output). 0 indicates "debug mode".
Gzip compression level: 0=debug, 1=fast, 9=best
gzip_stack_buffer
Unit: kilobytes
Default: 2048
- Units: Bytes
- Default: 32768
- Flags: experimental
Size of stack buffer used for in transit gzip processing, like
on the fly decompression.
Size of stack buffer used for gzip processing.
The stack 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_tmp_space
Default: 0
Where temporary space for gzip/gunzip is allocated.
0 - malloc
1 - session workspace
2 - thread workspace
If you have much gzip/gunzip activity, it may be an advantage to
use workspace for these allocations to reduce malloc activity.
Be aware that gzip needs 256+KB and gunzip" needs 32+KB of
workspace (64+KB if ESI processing).
- Default: 0
- Flags: experimental
http_headers
Units: header lines
Default: 64
Where temporary space for gzip/gunzip is allocated::
Maximum number of HTTP headers we will deal with.
This space is preallocated in sessions and workthreads only objects allocate only space for the headers
they store.
0 - malloc
1 - session workspace
2 - thread workspace
If you have much gzip/gunzip activity, it may be an advantage to use workspace for these allocations to reduce malloc activity. Be aware that gzip needs 256+KB and gunzip needs 32+KB of workspace (64+KB if ESI processing).
http_gzip_support
Default: on
- Units: bool
- Default: on
- Flags: experimental
Enable gzip support. When enabled Varnish will compress
uncompressed objects before they are stored in the cache. 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:
Enable gzip support. When enabled Varnish will compress uncompressed objects before they are stored in the cache. 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
Accept-Encoding: gzip
Clients that do not support gzip will have their Accept-Encoding
header removed. For more information no how gzip is implemted
please see the chapter on gzip in the Varnish reference.
Clients that do not support gzip will have their Accept-Encoding header removed. For more information no how gzip is implemted please see the chapter on gzip in the Varnish reference.
http_range
Default: off
Enables experimental support for the HTTP range header, enabling Varnish to serve parts of
an object to a client. However, Varnish will request the whole object from the backend server.
http_headers
- Units: header lines
- Default: 64
Maximum number of HTTP headers we will deal with.
This space is preallocated in sessions and workthreads only objects allocate only space for the headers they store.
http_range_support
- Units: bool
- Default: off
- Flags: experimental
Enable support for HTTP Range headers.
listen_address
Default: :80
Flags: must_restart
- Default: :80
- Flags: must_restart
Whitespace separated list of network endpoints where Varnish will accept requests.
Possible formats: host, host:port, :port
Whitespace separated list of network endpoints where Varnish will accept requests.
Possible formats: host, host:port, :port
listen_depth
Units: connections
Default: 1024
Flags: must_restart
- Units: connections
- Default: 1024
- Flags: must_restart
Listen queue depth.
Listen queue depth.
log_hashstring
Units: bool
Default: off
- Units: bool
- Default: off
Log the hash string to shared memory log.
Log the hash string to shared memory log.
log_local_address
Units: bool
Default: off
- Units: bool
- Default: off
Log the local address on the TCP connection in the SessionOpen shared memory record.
Log the local address on the TCP connection in the SessionOpen shared memory record.
lru_interval
Units: seconds
Default: 2
Flags: experimental
- Units: seconds
- Default: 2
- 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.
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_includes
Units: includes
Default: 5
- Units: includes
- Default: 5
Maximum depth of esi:include processing.
Maximum depth of esi:include processing.
max_restarts
Units: restarts
Default: 4
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.
overflow_max
Units: %
Default: 100
Flags: experimental
- Units: restarts
- Default: 4
Percentage permitted overflow queue length.
This sets the ratio of queued requests to worker threads, above which sessions will be dropped instead of
queued.
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.
ping_interval
Units: seconds
Default: 3
Flags: must_restart
- Units: seconds
- Default: 3
- 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.
Interval between pings from parent to child.
Zero will disable pinging entirely, which makes it possible to attach a debugger to the child.
pipe_timeout
Units: seconds
Default: 60
- Units: seconds
- Default: 60
Idle timeout for PIPE sessions. If nothing have been received in either direction for this many seconds,
the session is closed.
Idle timeout for PIPE sessions. If nothing have been received in either direction for this many seconds, the session is closed.
prefer_ipv6
Units: bool
Default: off
- Units: bool
- Default: off
Prefer IPv6 address when connecting to backends which have both IPv4 and IPv6 addresses.
Prefer IPv6 address when connecting to backends which have both IPv4 and IPv6 addresses.
queue_max
- Units: %
- Default: 100
- Flags: experimental
purge_dups
Units: bool
Default: on
Percentage permitted queue length.
Detect and eliminate duplicate purges.
This sets the ratio of queued requests to worker threads, above which sessions will be dropped instead of queued.
rush_exponent
Units: requests per request
Default: 3
Flags: experimental
- Units: requests per request
- Default: 3
- 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.
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.
saintmode_threshold
Units: objects
Default: 10
Flags: experimental
The maximum number of objects held off by saint mode before no further will be made to the backend until
one times out. A value of 0 disables saintmode.
send_timeout
Units: seconds
Default: 600
Flags: delayed
- Units: objects
- Default: 10
- Flags: experimental
Send timeout for client connections. If no data has been sent to the client in this many seconds, the ses‐
sion is closed.
See setsockopt(2) under SO_SNDTIMEO for more information.
The maximum number of objects held off by saint mode before no further will be made to the backend until one times out. A value of 0 disables saintmode.
sendfile_threshold
Units: bytes
Default: -1
Flags: experimental
send_timeout
- Units: seconds
- Default: 600
- Flags: delayed
The minimum size of objects transmitted with sendfile.
Send timeout for client connections. If no data has been sent to the client in this many seconds, the session is closed.
See setsockopt(2) under SO_SNDTIMEO for more information.
sess_timeout
Units: seconds
Default: 5
- Units: seconds
- Default: 5
Idle timeout for persistent sessions. If a HTTP request has not been received in this many seconds, the
session is closed.
Idle timeout for persistent sessions. If a HTTP request has not been received in this many seconds, the session is closed.
sess_workspace
Units: bytes
Default: 65536
Flags: delayed
- Units: bytes
- Default: 65536
- Flags: delayed
Bytes of HTTP protocol workspace allocated for sessions. This space must be big enough for the entire HTTP
protocol header and any edits done to it in the VCL code.
Minimum is 1024 bytes.
Bytes of HTTP protocol workspace allocated for sessions. This space must be big enough for the entire HTTP protocol header and any edits done to it in the VCL code.
Minimum is 1024 bytes.
session_linger
Units: ms
Default: 50
Flags: experimental
- Units: ms
- Default: 50
- Flags: experimental
How long time the workerthread lingers on the session to see if a new request appears right away.
If 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.
How long time the workerthread lingers on the session to see if a new request appears right away.
If 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.
session_max
Units: sessions
Default: 100000
- Units: sessions
- Default: 100000
Maximum number of sessions we will allocate 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.
Maximum number of sessions we will allocate 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
Units: bytes
Default: 255
- Units: bytes
- Default: 255
Maximum number of bytes in SHM log record.
Maximum is 65535 bytes.
Maximum number of bytes in SHM log record.
Maximum is 65535 bytes.
shm_workspace
Units: bytes
Default: 8192
Flags: delayed
- Units: bytes
- Default: 8192
- Flags: delayed
Bytes of shmlog workspace allocated for worker threads. If too big, it wastes some ram, if too small it causes needless flushes of the SHM workspace.
These flushes show up in stats as "SHM flushes due to overflow".
Minimum is 4096 bytes.
shortlived
- Units: s
- Default: 10.0
Bytes of shmlog workspace allocated for worker threads. If too big, it wastes some ram, if too small it
causes needless flushes of the SHM workspace.
These flushes show up in stats as "SHM flushes due to overflow".
Minimum is 4096 bytes.
Objects created with TTL shorter than this are always put in transient storage.
syslog_cli_traffic
Units: bool
Default: on
- Units: bool
- Default: on
Log all CLI traffic to syslog(LOG_INFO).
Log all CLI traffic to syslog(LOG_INFO).
thread_pool_add_delay
Units: milliseconds
Default: 20
Flags: experimental
- Units: milliseconds
- Default: 20
- Flags: experimental
Wait at least this long between creating threads.
Wait at least this long between creating threads.
Setting this too long results in insuffient worker threads.
Setting this too long results in insuffient worker threads.
Setting this too short increases the risk of worker thread pile-up.
Setting this too short increases the risk of worker thread pile-up.
thread_pool_add_threshold
Units: requests
Default: 2
Flags: experimental
- Units: requests
- Default: 2
- Flags: experimental
Overflow threshold for worker thread creation.
Overflow threshold for worker thread creation.
Setting this too low, will result in excess worker threads, which is generally a bad idea.
Setting this too low, will result in excess worker threads, which is generally a bad idea.
Setting it too high results in insuffient worker threads.
Setting it too high results in insuffient worker threads.
thread_pool_fail_delay
Units: milliseconds
Default: 200
Flags: experimental
- Units: milliseconds
- Default: 200
- Flags: experimental
Wait at least this long after a failed thread creation before trying to create another thread.
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 RAM resources for thread stacks.
This delay tries to not rush it on needlessly.
Failure to create a worker thread is often a sign that the end is near, because the process is running out of RAM resources for thread stacks.
This delay tries to not rush it on needlessly.
If thread creation failures are a problem, check that thread_pool_max is not too high.
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.
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: 500
Flags: delayed, experimental
- Units: threads
- Default: 500
- Flags: delayed, experimental
The maximum number of worker threads in all pools combined.
The maximum number of worker threads in all pools combined.
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.
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: 5
Flags: delayed, experimental
- Units: threads
- Default: 5
- Flags: delayed, experimental
The minimum number of threads in each worker pool.
The minimum number of threads in each worker pool.
Increasing this may help ramp up faster from low load situations where threads have expired.
Increasing this may help ramp up faster from low load situations where threads have expired.
Minimum is 2 threads.
Minimum is 2 threads.
thread_pool_purge_delay
Units: milliseconds
Default: 1000
Flags: delayed, experimental
- Units: milliseconds
- Default: 1000
- Flags: delayed, experimental
Wait this long between purging threads.
Wait this long between purging threads.
This controls the decay of thread pools when idle(-ish).
This controls the decay of thread pools when idle(-ish).
Minimum is 100 milliseconds.
Minimum is 100 milliseconds.
thread_pool_stack
Units: bytes
Default: -1
Flags: experimental
- Units: bytes
- Default: -1
- Flags: experimental
Worker thread stack size. In particular on 32bit systems you may need to tweak this down to fit many
threads into the limited address space.
Worker thread stack size.
On 32bit systems you may need to tweak this down to fit many threads into the limited address space.
thread_pool_timeout
Units: seconds
Default: 300
Flags: delayed, experimental
- Units: seconds
- Default: 300
- Flags: delayed, experimental
Thread idle threshold.
Thread idle threshold.
Threads in excess of thread_pool_min, which have been idle for at least this long are candidates for purg‐
ing.
Threads in excess of thread_pool_min, which have been idle for at least this long are candidates for purging.
Minimum is 1 second.
Minimum is 1 second.
thread_pools
Units: pools
Default: 2
Flags: delayed, experimental
- Units: pools
- Default: 2
- Flags: delayed, experimental
Number of worker thread pools.
Number of worker thread pools.
Increasing number of worker pools decreases lock contention.
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.
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.
Can be increased on the fly, but decreases require a restart to take effect.
thread_stats_rate
Units: requests
Default: 10
Flags: experimental
- Units: requests
- Default: 10
- Flags: experimental
Worker threads accumulate statistics, and dump these into the global stats counters if the lock is free
when they finish a request.
This parameters defines the maximum number of requests a worker thread may handle, before it is forced to
dump its accumulated stats into the global counters.
Worker threads accumulate statistics, and dump these into the global stats counters if the lock is free when they finish a request.
This parameters defines the maximum number of requests a worker thread may handle, before it is forced to dump its accumulated stats into the global counters.
user Default: .....
Flags: must_restart
user
- Default: magic
- Flags: must_restart
The unprivileged user to run as. Setting this will also set "group" to the specified user's primary group.
The unprivileged user to run as. Setting this will also set "group" to the specified user's primary group.
vcc_err_unref
- Units: bool
- Default: on
Unreferenced VCL objects result in error.
vcl_dir
- Default: /usr/local/etc/varnish
Directory from which relative VCL filenames (vcl.load and include) are opened.
vcl_trace
Units: bool
Default: off
- Units: bool
- Default: off
Trace VCL execution in the shmlog.
Enabling this will allow you to see the path each request has taken through the VCL program.
This generates a lot of logrecords so it is off by default.
vmod_dir
- Default: /usr/local/lib/varnish/vmods
Trace VCL execution in the shmlog.
Enabling this will allow you to see the path each request has taken through the VCL program.
This generates a lot of logrecords so it is off by default.
