varnishd

HTTP accelerator daemon

SYNOPSIS

varnishd [-a address[:port]] [-b host[:port]] [-C] [-d] [-f config]

[-F] [-g group] [-h type[,options]] [-i identity] [-l shl[,free[,fill]]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...] [-s [name=]kind[,options]] [-S secret-file] [-T address[:port]] [-t ttl] [-u user] [-V]

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 specified 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 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.
-F	Run in the foreground.
-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 shl[,free[,fill]]

Specifies size of shmlog file. shl is the store for the shared memory log records [80m], free is the store for other allocations [1m] and fill determines how the log is [+]. Scaling suffixes like ‘k’, ‘m’ can be used up to (e)tabytes. Default is 80 Megabytes.

-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.

-n name	Specify the 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.

-r param[,param...]

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 user, group, cc_command, vcc_allow_inline_c read only as these can potentially be used to escalate privileges from the CLI. Protecting listen_address may also be a good idea.

-s [name=]type[,options]

Use the specified storage backend. The storage backends can be one of the following:

• malloc[,size]
• file[,path[,size[,granularity]]]
• persistent,path,size

See Storage Types in the Users Guide for more information on the various storage backends. This option can be used multiple times to specify multiple storage files. Names are referenced in logs, vcl, statistics, etc.

-S file

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

-T address[:port]

Offer a management interface on the specified address and port. See Management Interface for a list of management commands.

-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 runtime parameter. If specifying both a user and a group, the user should be specified f.txt.
-V	Display the version number and exit.

Hash Algorithms

The following hash algorithms are available:

critbit

A 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.

simple_list

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

classic[,buckets]

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.

Storage Types

The following storage types are available:

malloc

syntax: malloc[,size]

malloc is a memory based backend.

file

syntax: file[,path[,size[,granularity]]]

The file backend stores data in a file on disk. The file will be accessed using mmap.

persistent (experimental)

syntax: persistent,path,size

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.

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.

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 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) 2007-2014 Varnish Software AS