Provided by: varnish_3.0.5-2ubuntu0.1_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]
          Malloc  is  a memory based backend. Each object will be allocated from memory. If your system runs low
          on memory swap will be used. Be aware that the size limitation only limits the actual storage and that
          approximately 1k of memory per object will be used for various internal structures.

          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.

          Mallocs performance is bound by memory speed so it is very fast.

       file[,path[,size[,granularity]]]
          The file backend stores objects in memory backed by a file on disk with  mmap.  This  is  the  default
          storage  backend  and  unless  you  specify  another  storage  this one will used along with Transient
          storage.

          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.

          File performance is typically limited by the write speed of the device, and depending on use, the seek
          time.

       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   workspace_client   (=16k),
       thread_pool_workspace  (=16k),  http_resp_size  (=8k),  http_req_size (=12k), gzip_stack_buffer (=4k) 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.
                 0x00080000 - ban-lurker debugging.
                 0x80000000 - do edge-detection on digest.

       System Message: WARNING/2 (../../doc/sphinx/reference/params.rst:, line 132)
              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 144)
              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 207)
              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 222)
              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

              Enable support for HTTP Range headers.

       http_req_hdr_len

              • Units: bytes

              • Default: 8192

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

       http_resp_hdr_len

              • Units: bytes

              • Default: 8192

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

       idle_send_timeout

              • Units: seconds

              • Default: 60

              • Flags: delayed

              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.

       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: 50

              • Flags: experimental

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

       pcre_match_limit

              • Default: 10000

              The limit for the  number of internal matching function calls in a pcre_exec() execution.

       pcre_match_limit_recursion

              • Default: 10000

              The limit for the  number of internal matching function recursions in a pcre_exec() execution.

       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: 600

              • 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.

       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

1.0                                                2010-05-31                                        VARNISHD(1)