.. Copyright (c) 2010-2020 Varnish Software AS SPDX-License-Identifier: BSD-2-Clause See LICENSE file for full text of license .. role:: ref(emphasis) .. _varnishd(1): ======== varnishd ======== ----------------------- HTTP accelerator daemon ----------------------- :Manual section: 1 SYNOPSIS ======== varnishd [-a [name=][listen_address[,PROTO]] [-b [host[:port]|path]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl] [-M address:port] [-n workdir] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter] varnishd [-x parameter|vsl|cli|builtin|optstring] varnishd [-?] DESCRIPTION =========== The `varnishd` daemon accepts HTTP requests from clients, passes them on to a backend server and caches the returned documents to better satisfy future requests for the same document. .. _ref-varnishd-options: OPTIONS ======= Basic options ------------- -a <[name=][listen_address[,PROTO]]> Accept for client requests on the specified listen_address (see below). Name is referenced in logs. If name is not specified, "a0", "a1", etc. is used. PROTO can be "HTTP" (the default) or "PROXY". Both version 1 and 2 of the proxy protocol can be used. Multiple -a arguments are allowed. If no -a argument is given, the default `-a :80` will listen to all IPv4 and IPv6 interfaces. -a <[name=][ip_address][:port][,PROTO]> The ip_address can be a host name ("localhost"), an IPv4 dotted-quad ("127.0.0.1") or an IPv6 address enclosed in square brackets ("[::1]") If port is not specified, port 80 (http) is used. At least one of ip_address or port is required. -a <[name=][path][,PROTO][,user=name][,group=name][,mode=octal]> (VCL4.1 and higher) Accept connections on a Unix domain socket. Path must be absolute ("/path/to/listen.sock"). The user, group and mode sub-arguments may be used to specify the permissions of the socket file -- use names for user and group, and a 3-digit octal value for mode. -b <[host[:port]|path]> Use the specified host as backend server. If port is not specified, the default is 8080. If the value of ``-b`` begins with ``/``, it is interpreted as the absolute path of a Unix domain socket to which Varnish connects. In that case, the value of ``-b`` must satisfy the conditions required for the ``.path`` field of a backend declaration, see :ref:`vcl(7)`. Backends with Unix socket addresses may only be used with VCL versions >= 4.1. -b can be used only once, and not together with f. -f config Use the specified VCL configuration file instead of the builtin default. See :ref:`vcl(7)` for details on VCL syntax. If a single -f option is used, then the VCL instance loaded from the file is named "boot" and immediately becomes active. If more than one -f option is used, the VCL instances are named "boot0", "boot1" and so forth, in the order corresponding to the -f arguments, and the last one is named "boot", which becomes active. Either -b or one or more -f options must be specified, but not both, and they cannot both be left out, unless -d is used to start `varnishd` in debugging mode. If the empty string is specified as the sole -f option, then `varnishd` starts without starting the worker process, and the management process will accept CLI commands. You can also combine an empty -f option with an initialization script (-I option) and the child process will be started if there is an active VCL at the end of the initialization. When used with a relative file name, config is searched in the ``vcl_path``. It is possible to set this path prior to using ``-f`` options with a ``-p`` option. During startup, `varnishd` doesn't complain about unsafe VCL paths: unlike the `varnish-cli(7)` that could later be accessed remotely, starting `varnishd` requires local privileges. .. _opt_n: -n workdir Runtime directory for the shared memory, compiled VCLs etc. In performance critical applications, this directory should be on a RAM backed filesystem. Relative paths will be appended to `/var/run/` (NB: Binary packages of Varnish may have adjusted this to the platform.) The default value is `/var/run/varnishd` (NB: as above.) Documentation options --------------------- For these options, `varnishd` prints information to standard output and exits. When a -x option is used, it must be the only option (it outputs documentation in reStructuredText, aka RST). -? Print the usage message. -x parameter Print documentation of the runtime parameters (-p options), see `List of Parameters`_. -x vsl Print documentation of the tags used in the Varnish shared memory log, see :ref:`vsl(7)`. -x cli Print documentation of the command line interface, see :ref:`varnish-cli(7)`. -x builtin Print the contents of the default VCL program ``builtin.vcl``. -x optstring Print the optstring parameter to ``getopt(3)`` to help writing wrapper scripts. Operations options ------------------ -F Do not fork, run in the foreground. Only one of -F or -d can be specified, and -F cannot be used together with -C. -T Offer a management interface on the specified address and port. See :ref:`varnish-cli(7)` for documentation of the management commands. To disable the management interface use ``none``. -M Connect to this port and offer the command line interface. Think of it as a reverse shell. When running with -M and there is no backend defined the child process (the cache) will not start initially. -P file Write the PID of the process to the specified file. -i identity Specify the identity of the Varnish server. This can be accessed using ``server.identity`` from VCL and with VSM_Name() from utilities. If not specified the output of gethostname(3) is used. -I clifile Execute the management commands in the file given as ``clifile`` before the the worker process starts, see `CLI Command File`_. Tuning options -------------- -t TTL Specifies the default time to live (TTL) for cached objects. This is a shortcut for specifying the *default_ttl* run-time parameter. -p Set the parameter specified by param to the specified value, see `List of Parameters`_ for details. This option can be used multiple times to specify multiple parameters. -s <[name=]type[,options]> Use the specified storage backend. See `Storage Backend`_ section. This option can be used multiple times to specify multiple storage files. Name is referenced in logs, VCL, statistics, etc. If name is not specified, "s0", "s1" and so forth is used. -l Specifies size of the space for the VSL records, shorthand for ``-p vsl_space=``. Scaling suffixes like 'K' and 'M' can be used up to (G)igabytes. See `vsl_space`_ for more information. Security options ---------------- -r Make the listed parameters read only. This gives the system administrator a way to limit what the Varnish CLI can do. Consider making parameters such as *cc_command*, *vcc_allow_inline_c* and *vmod_path* read only as these can potentially be used to escalate privileges from the CLI. -S secret-file Path to a file containing a secret used for authorizing access to the management port. To disable authentication use ``none``. If this argument is not provided, a secret drawn from the system PRNG will be written to a file called ``_.secret`` in the working directory (see `opt_n`_) with default ownership and permissions of the user having started varnish. Thus, users wishing to delegate control over varnish will probably want to create a custom secret file with appropriate permissions (ie. readable by a unix group to delegate control to). -j Specify the jailing mechanism to use. See `Jail`_ section. Advanced, development and debugging options ------------------------------------------- -d Enables debugging mode: The parent process runs in the foreground with a CLI connection on stdin/stdout, and the child process must be started explicitly with a CLI command. Terminating the parent process will also terminate the child. Only one of -d or -F can be specified, and -d cannot be used together with -C. -C Print VCL code compiled to C language and exit. Specify the VCL file to compile with the -f option. Either -f or -b must be used with -C, and -C cannot be used with -F or -d. -V Display the version number and exit. This must be the only option. -h Specifies the hash algorithm. See `Hash Algorithm`_ section for a list of supported algorithms. -W waiter Specifies the waiter type to use. .. _opt_h: Hash Algorithm -------------- The following hash algorithms are available: -h critbit self-scaling tree structure. The default hash algorithm in Varnish Cache 2.1 and onwards. In comparison to a more traditional B tree the critbit tree is almost completely lockless. Do not change this unless you are certain what you're doing. -h simple_list A simple doubly-linked list. Not recommended for production use. -h A standard hash table. The hash key is the CRC32 of the object's URL modulo the size of the hash table. Each table entry points to a list of elements which share the same hash key. The buckets parameter specifies the number of entries in the hash table. The default is 16383. .. _ref-varnishd-opt_s: Storage Backend --------------- The argument format to define storage backends is: -s <[name]=kind[,options]> If *name* is omitted, Varnish will name storages ``s``\ *N*, starting with ``s0`` and incrementing *N* for every new storage. For *kind* and *options* see details below. Storages can be used in vcl as ``storage.``\ *name*, so, for example if ``myStorage`` was defined by ``-s myStorage=malloc,5G``, it could be used in VCL like so:: set beresp.storage = storage.myStorage; A special *name* is ``Transient`` which is the default storage for uncacheable objects as resulting from a pass, hit-for-miss or hit-for-pass. If no ``-s`` options are given, the default is:: -s default,100m If no ``Transient`` storage is defined, the default is an unbound ``default`` storage as if defined as:: -s Transient=default The following storage types and options are available: -s The default storage type resolves to ``umem`` where available and ``malloc`` otherwise. -s malloc is a memory based backend. -s umem is a storage backend which is more efficient than malloc on platforms where it is available. See the section on umem in chapter `Storage backends` of `The Varnish Users Guide` for details. -s The file backend stores data in a file on disk. The file will be accessed using mmap. Note that this storage provide no cache persistence. The path is mandatory. If path points to a directory, a temporary file will be created in that directory and immediately unlinked. If path points to a non-existing file, the file will be created. If size is omitted, and path points to an existing file with a size greater than zero, the size of that file will be used. If not, an error is reported. Granularity sets the allocation block size. Defaults to the system page size or the filesystem block size, whichever is larger. Advice tells the kernel how `varnishd` expects to use this mapped region so that the kernel can choose the appropriate read-ahead and caching techniques. Possible values are ``normal``, ``random`` and ``sequential``, corresponding to MADV_NORMAL, MADV_RANDOM and MADV_SEQUENTIAL madvise() advice argument, respectively. Defaults to ``random``. -s Persistent storage. Varnish will store objects in a file in a manner that will secure the survival of *most* of the objects in the event of a planned or unplanned shutdown of Varnish. The persistent storage backend has multiple issues with it and will likely be removed from a future version of Varnish. .. _ref-varnishd-opt_j: Jail ---- Varnish jails are a generalization over various platform specific methods to reduce the privileges of varnish processes. They may have specific options. Available jails are: -j Reduce `privileges(5)` for `varnishd` and sub-process to the minimally required set. Only available on platforms which have the `setppriv(2)` call. The optional `worker` argument can be used to pass a privilege-specification (see `ppriv(1)`) by which to extend the effective set of the varnish worker process. While extended privileges may be required by custom vmods, it is always the more secure to *not* use the `worker` option. Example to grant basic privileges to the worker process:: -j solaris,worker=basic -j Default on all other platforms when `varnishd` is started with an effective uid of 0 ("as root"). With the ``unix`` jail mechanism activated, varnish will switch to an alternative user for subprocesses and change the effective uid of the master process whenever possible. The optional `user` argument specifies which alternative user to use. It defaults to ``varnish``. The optional `ccgroup` argument specifies a group to add to varnish subprocesses requiring access to a c-compiler. There is no default. The optional `workuser` argument specifies an alternative user to use for the worker process. It defaults to ``vcache``. -j none last resort jail choice: With jail mechanism ``none``, varnish will run all processes with the privileges it was started with. .. _ref-varnishd-opt_T: 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 :ref:`varnishadm(1)`. The commands available are documented in :ref:`varnish-cli(7)`. CLI Command File ---------------- The -I option makes it possible to run arbitrary management commands when `varnishd` is launched, before the worker process is started. In particular, this is the way to load configurations, apply labels to them, and make a VCL instance active that uses those labels on startup:: vcl.load panic /etc/varnish_panic.vcl vcl.load siteA0 /etc/varnish_siteA.vcl vcl.load siteB0 /etc/varnish_siteB.vcl vcl.load siteC0 /etc/varnish_siteC.vcl vcl.label siteA siteA0 vcl.label siteB siteB0 vcl.label siteC siteC0 vcl.load main /etc/varnish_main.vcl vcl.use main Every line in the file, including the last line, must be terminated by a newline or carriage return. If a command in the file is prefixed with '-', failure will not abort the startup. Note that it is necessary to include an explicit `vcl.use` command to select which VCL should be the active VCL when relying on CLI Command File to load the configurations at startup. .. _ref-varnishd-params: RUN TIME PARAMETERS =================== Run Time Parameter Flags ------------------------ Runtime parameters are marked with shorthand flags to avoid repeating the same text over and over in the table below. The meaning of the flags are: * `experimental` We have no solid information about good/bad/optimal values for this parameter. Feedback with experience and observations are most welcome. * `delayed` This parameter can be changed on the fly, but will not take effect immediately. * `restart` The worker process must be stopped and restarted, before this parameter takes effect. * `reload` The VCL programs must be reloaded for this parameter to take effect. * `wizard` Do not touch unless you *really* know what you're doing. * `only_root` Only works if `varnishd` is running as root. Default Value Exceptions on 32 bit Systems ------------------------------------------ Be aware that on 32 bit systems, certain default or maximum values are reduced relative to the values listed below, in order to conserve VM space: * workspace_client: 24k * workspace_backend: 20k * http_resp_size: 8k * http_req_size: 12k * gzip_buffer: 4k * vsl_buffer: 4k * vsl_space: 1G (maximum) * thread_pool_stack: 64k .. _List of Parameters: List of Parameters ------------------ This text is produced from the same text you will find in the CLI if you use the param.show command: .. include:: ../include/params.rst EXIT CODES ========== Varnish and bundled tools will, in most cases, exit with one of the following codes * `0` OK * `1` Some error which could be system-dependent and/or transient * `2` Serious configuration / parameter error - retrying with the same configuration / parameters is most likely useless The `varnishd` master process may also OR its exit code * with `0x20` when the `varnishd` child process died, * with `0x40` when the `varnishd` child process was terminated by a signal and * with `0x80` when a core was dumped. SEE ALSO ======== * :ref:`varnishlog(1)` * :ref:`varnishhist(1)` * :ref:`varnishncsa(1)` * :ref:`varnishstat(1)` * :ref:`varnishtop(1)` * :ref:`varnish-cli(7)` * :ref:`vcl(7)` HISTORY ======= The `varnishd` daemon was developed by Poul-Henning Kamp in cooperation with Verdens Gang AS and Varnish Software. This manual page was written by Dag-Erling Smørgrav with updates by Stig Sandbeck Mathisen , Nils Goroll and others. COPYRIGHT ========= This document is licensed under the same licence as Varnish itself. See LICENCE for details. * Copyright (c) 2007-2015 Varnish Software AS