man ejabberd (8): a distributed fault-tolerant Jabber/XMPP server

SYNOPSIS

ejabberd [options] [--] [erlang_options]

DESCRIPTION

ejabberd is a distributed fault-tolerant Jabber/XMPP server written in Erlang.

Its main features are:

--- XMPP-compliant
--- Distributed: ejabberd can run on a cluster of machines
--- Fault-tolerant: All the information can be stored on more than one node, nodes can be added or replaced `on the fly'
--- Built-in Multi-User Chat service
--- Built-in IRC transport
--- Built-in Publish-Subscribe service
--- Built-in Jabber User Directory service based on users vCards
--- SSL support
--- Support for internationalized user messages

OPTIONS

--node node

Specifies Erlang node at which ejabberd server will be run. Default node is ejabberd. If the node name does not contain symbol @ then actual node name becomes node@hostname where hostname is short host name (usually it coincides with `hostname -s`). If the node name contain symbol @ and its hostname part is a FQDN then ejabberd will use so-called long names (see erl(1) manual page and look for options -name and -sname for details).

Examples of --node option:

ejabberd Locally run ejabberd server at node ejabberd@`hostname -s`.

ejabberd@otherhost Pretend that ejabberd server runs at otherhost at node ejabberd@otherhost. (Note that noone can remotely connect to this node if otherhost is resoved to other computer IP.)

ejabberd@localhost Locally run ejabberd server at node ejabberd@localhost. Only nodes running at the same host can connect to this node.

[email protected] Using -name Erlang option, run ejabberd server at long-name node [email protected]. To be able to control this server instance hostname.domainname must resolve (either by DNS or via /etc/hosts) to the server's IP.

The default node can be overridden by defining ERLANG_NODE environment variable in /etc/default/ejabberd, see below.

--config config-file

Specifies an alternate config-file to be parsed at startup, rather than the default (/etc/ejabberd/ejabberd.cfg).

--spool spool-dir

Specifies an alternate spool-dir to store user database instead of the default (/var/lib/ejabberd).

--log log-file

Log Jabber events to specified log-file rather than to the default (/var/log/ejabberd/ejabberd.log).

--erlang-log sasl-log-file

Log SASL (System Application Support Libraries) events to specified sasl-log-file rather than to the default (/var/log/ejabberd/erlang.log).

erlang_options

Other options (and all options following --) are passed directly to Erlang interpreter. See Erlang documentation for more details on interpreter options. Some useful options are:

-detached
    Starts the Erlang system detached from the system console.
-heart
    Starts heart beat monitoring of the Erlang system.
-noinput
    Ensures that the Erlang system never tries to read any input.

CONFIGURATION FILE

The file /etc/ejabberd/ejabberd.cfg contains the main configuration. It is initially loaded the first time ejabberd is executed, then it is parsed and stored in a database. Subsiquently the configuration is loaded from the database and any commands in the configuration file are appended to the entries in the database. The configuration file consists of a sequence of Erlang terms. Parts of lines after `%' sign are ignored. Each term is a tuple, where the first element is the name of an option, and the others are option values. E. g. if this file does not contain a "host" definition, then the value stored in the database will be used.

To override old values stored in the database the following lines can be added in config:

  override_global.

  override_local.

  override_acls.

A complete explanation of each configuration value can be found in the official ejabberd documentation. See "SEE ALSO" part of this manual page for more information about the documentation.

OPTIONS FILE

The file /etc/default/ejabberd contains specific options.

POLL

If set to true this variable enables kernel polling which can reduce CPU load on a system with a high number of users. This option requires support in the kernel and in Erlang emulator.

SMP

Enables or disables SMP support in Erlang emulator. Valid values are disable (default), auto, and enable.

Explanation in Erlang/OTP documentation:

enable: Starts the Erlang runtime system with SMP support enabled. This may fail if no runtime system with SMP support is available.
auto: Starts the Erlang runtime system with SMP support enabled if it is available and more than one logical processor are detected.
disable: Starts a runtime system without SMP support.

ERL_MAX_PORTS

To use more than 1024 connections (default value), ERL_MAX_PORTS should be set to the number of connections needed.

PROCESSES

Specifies the maximum number of Erlang processes to use. Default value is 250000. Maximum value is 268435456. Ejabberd uses up to three processes per user or server connection.

ERL_MAX_ETS_TABLES

Sets the maximum number of ETS and Mnesia tables. Default value is 1400 which should be sufficient for a sever without many custom modules. If a message ** Too many db tables ** appears in ejabberd log files then increase this number.

ERL_OPTIONS

With this option, parameters can be passed to Erlang interpretor. See Erlang documentation for more details on interpreter options.

ERL_FULLSWEEP_AFTER

To reduce memory usage when allowing a large number of connections, ERL_FULLSWEEP_AFTER may be set to 0 in the options file, but in this case ejabberd may start to work slower.

ERLANG_NODE

Use specified string as erlang node. It overrides default ejabberd node name. The string may take one of the following forms: nodename, nodename@hostname or [email protected]

FILES

/etc/ejabberd/ejabberd.cfg: default configuration file
/etc/default/ejabberd: default variables

BUGS

Ejabberd uses distributed Erlang mode to work properly. This means that on start it connects to epmd (Erlang port mapping daemon) which is listening at port 4369 and tries to register ejabberd node name. If the connection fails (known failure reasons are unavailability of a loopback interface or firewall issues) Erlang emulator fails to start with not very clear error message. If there's already started Erlang node with the same name (ejabberd by default) then ejabberd will also fail with a cryptic error message (in which one can find words {error,duplicate_name}). Another possible case when ejabberd cannot start is incorrect permissions of /var/lib/ejabberd directory (it must be writable by user ejabberd).

AUTHORS

This manual page was adapted by Christophe Romain <[email protected]> and Sergei Golovan <[email protected]> for the Debian system (but may be used by others) from the ejabberd documentation written by Alexey Shchepin <[email protected]>.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 any later version published by the Free Software Foundation.

On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.