Provided by: varnish_3.0.2-1_amd64 bug

NAME

       varnishd - HTTP accelerator daemon

SYNOPSIS

       varnishd [-a address[:port]] [-b host[:port]] [-d] [-F] [-f config]
              [-g  group]  [-h  type[,options]] [-i identity] [-l shmlogsize] [-n name] [-P file]
              [-p param=value] [-s type[,options]] [-T address[:port]] [-t ttl]  [-u  user]  [-V]
              [-w min[,max[,timeout]]]

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

       -a address[:port][,address[:port][...]
              Listen for client requests on the specified address and port.  The 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 address is not specified, varnishd  will
              listen  on  all  available IPv4 and IPv6 interfaces.  If port is not specified, the
              default HTTP port as listed in /etc/services is used.  Multiple listening addresses
              and ports can be speci‐ fied as a whitespace- or comma-separated list.

       -b host[:port]
              Use the specified host as backend server.  If port is not specified, the default is
              8080.

       -C     Print VCL code compiled to C language and exit. Specify the  VCL  file  to  compile
              with the -f option.

       -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.

       -F     Run in the foreground.

       -f config
              Use  the  specified  VCL  configuration  file  instead of the builtin default.  See
              vcl(7) for details on VCL syntax. When no configuration is supplied  varnishd  will
              not start the cache process.

       -g group
              Specifies  the  name  of  an  unprivileged  group to which the child process should
              switch before it starts accepting connections.  This is a shortcut  for  specifying
              the group run-time parameter.

       -h type[,options]
              Specifies  the  hash  algorithm.   See  Hash  Algorithms  for  a  list of supported
              algorithms.

       -i identity
              Specify  the  identity  of  the  varnish  server.   This  can  be  accessed   using
              server.identity from VCL

       -l shmlogsize
              Specify  size  of  shmlog  file.   Scaling suffixes like 'k', 'm' can be used up to
              (e)tabytes.  Default is 80 Megabytes.  Specifying less than 8 Megabytes is unwise.

       -n name
              Specify a name for this instance.  Amonst  other  things,  this  name  is  used  to
              construct  the  name  of  the directory in which varnishd keeps temporary files and
              persistent state.  If the specified  name  begins  with  a  forward  slash,  it  is
              interpreted  as  the  absolute  path to the directory which should be used for this
              purpose.

       -P file
              Write the process's PID to the specified file.

       -p param=value
              Set the parameter  specified  by  param  to  the  specified  value.   See  Run-Time
              Parameters  for  a  list  of  parameters. This option can be used multiple times to
              specify multiple parameters.

       -S file
              Path to a file containing a secret used for authorizing access  to  the  management
              port.

       -s [name=]type[,options]
              Use  the  specified  storage  backend.   See  Storage Types for a list of supported
              storage types.  This option can be used multiple times to specify multiple  storage
              files.  You  can  name  the  different  backends.  Varnish will then reference that
              backend with the given name in logs, statistics, etc.

       -T address[:port]
              Offer a management interface on the specified address  and  port.   See  Management
              Interface for a list of management commands.

       -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.

       -t ttl Specifies a hard minimum time to live for cached documents.  This is a shortcut for
              specifying the default_ttl run-time parameter.

       -u user
              Specifies the name of an unprivileged user to which the child process should switch
              before it starts accepting connections.  This is a shortcut for specifying the user
              run- time parameter.

              If specifying both a user and a group, the user should be specified first.

       -V     Display the version number and exit.

       -w min[,max[,timeout]]

          Start at least min but no more than max worker threads with the specified idle timeout.
          This   is   a   shortcut   for  specifying  the  thread_pool_min,  thread_pool_max  and
          thread_pool_timeout run-time parameters.

          If only one number is specified, thread_pool_min and thread_pool_max are  both  set  to
          this number, and thread_pool_timeout has no effect.

   Hash Algorithms
       The following hash algorithms are available:

       simple_list
              A simple doubly-linked list.  Not recommended for production use.

       classic[,buckets]
              A  standard  hash  table.   This  is the default.  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.

       critbit
              A self-scaling tree structure. The default hash algorithm in 2.1. In comparison  to
              a more traditional B tree the critbit tree is almost completely lockless.

   Storage Types
       The following storage types are available:

       malloc[,size]
              Storage for each object is allocated with malloc(3).

              The  size  parameter specifies the maximum amount of memory varnishd will allocate.
              The size is assumed to be in  bytes,  unless  followed  by  one  of  the  following
              suffixes:

              K, k    The size is expressed in kibibytes.

              M, m    The size is expressed in mebibytes.

              G, g    The size is expressed in gibibytes.

              T, t    The size is expressed in tebibytes.

              The default size is unlimited.

       file[,path[,size[,granularity]]]
              Storage  for  each object is allocated from an arena backed by a file.  This is the
              default.

              The path parameter specifies either the path to the backing file or the path  to  a
              directory in which varnishd will create the backing file.  The default is /tmp.

              The  size parameter specifies the size of the backing file.  The size is assumed to
              be in bytes, unless fol‐ lowed by one of the following suffixes:

              K, k    The size is expressed in kibibytes.

              M, m    The size is expressed in mebibytes.

              G, g    The size is expressed in gibibytes.

              T, t    The size is expressed in tebibytes.

              %       The size is expressed as a percentage of the free space on the file  system
              where it resides.

              The default size is 50%.

              If  the  backing  file  already  exists,  it  will  be truncated or expanded to the
              specified size.

              Note that if varnishd has to create or expand the file, it  will  not  pre-allocate
              the  added space, leading to fragmentation, which may adversely impact performance.
              Pre-creating the storage file using dd(1) will reduce fragmentation to a minimum.

              The granularity parameter specifies the granularity of allocation.  All allocations
              are  rounded  up to this size.  The size is assumed to be in bytes, unless followed
              by one of the suffixes described for size except for %.

              The default size is the VM page size.  The size should be reduced if you have  many
              small objects.

       persistent,path,size {experimental}

          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  path  parameter  specifies the path to the backing file. If the file doesn't exist
          Varnish will create it.

          The size parameter specifies the size of the backing file.  The size is assumed  to  be
          in bytes, unless followed by one of the following suffixes:

          K, k    The size is expressed in kibibytes.

          M, m    The size is expressed in mebibytes.

          G, g    The size is expressed in gibibytes.

          T, t    The size is expressed in tebibytes.

          Varnish  will split the file into logical silos and write to the silos in the manner of
          a circular buffer. Only one silo will be kept open at any given  point  in  time.  Full
          silos  are  sealed. When Varnish starts after a shutdown it will discard the content of
          any silo that isn't sealed.

   Transient Storage
          If you name any of your storage backend "Transient"  it  will  be  used  for  transient
          (short  lived)  objects.  By  default Varnish would use an unlimited malloc backend for
          this.

   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(7).

   Run-Time Parameters
       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.

       Here  is  a  list  of  all parameters, current as of last time we remembered to update the
       manual page.  This text is produced from the same text you will find in the CLI if you use
       the  param.show  command, so should there be a new parameter which is not listed here, you
       can find the description using the CLI commands.

       Be aware that on 32 bit systems, certain default values, such as sess_workspace (=16k) and
       thread_pool_stack  (=64k)  are  reduced  relative  to  the values listed here, in order to
       conserve VM space.

       acceptor_sleep_decay

              · 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%)

       acceptor_sleep_incr

              · 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.

       acceptor_sleep_max

              · 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.

       auto_restart

              · Units: bool

              · Default: on

              Restart child process automatically if it dies.

       ban_dups

              · Units: bool

              · Default: on

              Detect and eliminate duplicate bans.

       ban_lurker_sleep

              · Units: s

              · Default: 0.01

              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

              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.

       cc_command

              · Default: exec gcc -std=gnu99  -pthread -fpic -shared -Wl,-x -o %o %s

              · Flags: must_reload

              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

              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

              Timeout for the childs replies to CLI requests from the master.

       clock_skew

              · Units: s

              · Default: 10

              How much clockskew we are willing to accept between the backend and our own clock.

       connect_timeout

              · Units: s

              · Default: 0.7

              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:

              How long time the critbit hasher keeps deleted objheads on the cooloff list.

       default_grace

              · 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.   Objects  already  cached
              will not be affected by changes made until they are fetched from the backend again.

       default_keep

              · Units: seconds

              · Default: 0

              · Flags: delayed

              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: 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 "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.
              0x00010000 - synchronize shmlog.
              0x00020000 - synchronous start of persistence.
              0x00040000 - release VCL early.
              0x80000000 - do edge-detection on digest.

       System Message: WARNING/2 (../../doc/sphinx/reference/params.rst:, line 131)
              Literal block ends without a blank line; unexpected unindent.

              Use 0x notation and do the bitor in your head :-)

       esi_syntax

              · Units: bitmap

              · Default: 0

              Bitmap controlling ESI parsing code:

              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)

       System Message: WARNING/2 (../../doc/sphinx/reference/params.rst:, line 143)
              Literal block ends without a blank line; unexpected unindent.

              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.

       fetch_chunksize

              · 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.

       fetch_maxchunksize

              · Units: kilobytes

              · Default: 262144

              · 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: 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.

       group

              · Default: magic

              · Flags: must_restart

              The unprivileged group to run as.

       gzip_level

              · Default: 6

              Gzip compression level: 0=debug, 1=fast, 9=best

       gzip_memlevel

              · Default: 8

              Gzip memory level 1=slow/least, 9=fast/most compression.  Memory  impact  is  1=1k,
              2=2k, ... 9=256k.

       gzip_stack_buffer

              · Units: Bytes

              · Default: 32768

              · Flags: experimental

              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

              · Flags: experimental

              Where temporary space for gzip/gunzip is allocated:

              0 - malloc
              1 - session workspace
              2 - thread workspace

       System Message: WARNING/2 (../../doc/sphinx/reference/params.rst:, line 206)
              Literal block ends without a blank line; unexpected unindent.

              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).

       gzip_window

              · Default: 15

              Gzip window size 8=least, 15=most compression.  Memory impact is  8=1k,  9=2k,  ...
              15=128k.

       http_gzip_support

              · 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:

       System Message: WARNING/2 (../../doc/sphinx/reference/params.rst:, line 221)
              Literal block expected; none found.

              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

              · Units: header lines

              · Default: 64

              Maximum number of HTTP headers we will deal  with  in  client  request  or  backend
              reponses.   Note  that  the  first line occupies five header fields.  This paramter
              does not influence storage  consumption,  objects  allocate  exact  space  for  the
              headers they store.

       http_range_support

              · Units: bool

              · Default: on

              · Flags: experimental

              Enable support for HTTP Range headers.

       http_req_hdr_len

              · Units: bytes

              · Default: 4096

              Maximum  length  of  any  HTTP  client  request header we will allow.  The limit is
              inclusive its continuation lines.

       http_req_size

              · Units: bytes

              · Default: 32768

              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 session workspace (param: sess_workspace) and
              this parameter limits how much of that the request is allowed to take up.

       http_resp_hdr_len

              · Units: bytes

              · Default: 4096

              Maximum  length  of  any  HTTP backend response header we will allow.  The limit is
              inclusive its continuation lines.

       http_resp_size

              · Units: bytes

              · Default: 32768

              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: sess_workspace)  and
              this parameter limits how much of that the request is allowed to take up.

       listen_address

              · Default: :80

              · Flags: must_restart

              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

              Listen queue depth.

       log_hashstring

              · Units: bool

              · Default: on

              Log the hash string components to shared memory log.

       log_local_address

              · Units: bool

              · Default: off

              Log the local address on the  TCP  connection  in  the  SessionOpen  shared  memory
              record.

       lru_interval

              · 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.

       max_esi_depth

              · Units: levels

              · Default: 5

              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.

       nuke_limit

              · Units: allocations

              · Default: 10

              · Flags: experimental

              Maximum number of objects we attempt to nuke in orderto make  space  for  a  object
              body.

       ping_interval

              · 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.

       pipe_timeout

              · 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.

       prefer_ipv6

              · Units: bool

              · Default: off

              Prefer  IPv6  address  when  connecting  to  backends which have both IPv4 and IPv6
              addresses.

       queue_max

              · Units: %

              · Default: 100

              · Flags: experimental

              Percentage permitted queue length.

              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

              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: 60

              · Flags: delayed

              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.

       sess_timeout

              · 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.

       sess_workspace

              · 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.

       session_linger

              · 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.

       session_max

              · 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.

       shm_reclen

              · Units: bytes

              · Default: 255

              Maximum number of bytes in SHM log record.  Maximum is 65535 bytes.

       shm_workspace

              · 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

              Objects created with TTL shorter than this are always put in transient storage.

       syslog_cli_traffic

              · Units: bool

              · Default: on

              Log all CLI traffic to syslog(LOG_INFO).

       thread_pool_add_delay

              · Units: milliseconds

              · Default: 2

              Wait at least this long between creating threads.

              Setting this too long results in insuffient worker threads.

              Setting this too short increases the risk of worker thread pile-up.

       thread_pool_add_threshold

              · Units: requests

              · Default: 2

              · Flags: experimental

              Overflow threshold for worker thread creation.

              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.

       thread_pool_fail_delay

              · Units: milliseconds

              · Default: 200

              · 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 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.

              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

              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: 5

              · Flags: delayed, experimental

              The minimum number of worker threads in each pool.

              Increasing this may help ramp up faster from low load situations where threads have
              expired.

              Minimum is 2 threads.

       thread_pool_purge_delay

              · Units: milliseconds

              · Default: 1000

              · Flags: delayed, experimental

              Wait this long between purging threads.

              This controls the decay of thread pools when idle(-ish).

              Minimum is 100 milliseconds.

       thread_pool_stack

              · Units: bytes

              · Default: -1

              · Flags: experimental

              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

              Thread idle threshold.

              Threads in excess of thread_pool_min, which have been idle for at least  this  long
              are candidates for purging.

              Minimum is 1 second.

       thread_pool_workspace

              · Units: bytes

              · Default: 65536

              · Flags: delayed

              Bytes  of  HTTP protocol workspace allocated for worker threads. This space must be
              big enough for the backend request and responses, and response to the  client  plus
              any other memory needs in the VCL code.Minimum is 1024 bytes.

       thread_pools

              · Units: pools

              · Default: 2

              · Flags: delayed, experimental

              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.

       thread_stats_rate

              · 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.

       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.

       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

              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

              Directory where VCL modules are to be found.

       waiter

              · Default: default

              · Flags: must_restart, experimental

              Select the waiter kernel interface.

SEE ALSO

       · varnish-cli(7)

       · varnishlog(1)

       · varnishhist(1)

       · varnishncsa(1)

       · varnishstat(1)

       · varnishtop(1)

       · vcl(7)

HISTORY

       The varnishd daemon was developed by Poul-Henning Kamp in cooperation  with  Verdens  Gang
       AS, Varnish Software AS and Varnish Software.

       This manual page was written by Dag-Erling Smørgrav with updates by Stig Sandbeck Mathisen
       ⟨ssm@debian.org

COPYRIGHT

       This document is licensed under the same  licence  as  Varnish  itself.  See  LICENCE  for
       details.

       · Copyright (c) 2007-2011 Varnish Software AS

AUTHOR

       Dag-Erling Smørgrav, Stig Sandbeck Mathisen, Per Buer