Options: Listen

The listen section specifies how MongooseIM handles incoming connections.

• Syntax: Each listener is specified in a subsection starting with [[listen.type]] where type is one of the allowed listener types, handling different types of incoming connections:

  • c2s - client-to-server XMPP connections,
  • s2s - server-to-server XMPP connections,
  • service - XMPP connections from external components,
  • http - HTTP connections from clients or other services.

The double-bracket syntax is used because there can be multiple listeners of a given type, so for each listener type there is a TOML array of one or more tables (subsections).

• Default: None - each listener needs to be enabled explicitly. Typical listeners are already specified in the example configuration file.
• Example: The simplest XMPP listener configuration, handling only incoming XMPP client connections:

[[listen.c2s]]
  port = 5222

General listener options

The options listed below are the same for all listener types. They set the basic listening socket options. Only port is required, the rest can be used to change the default settings.

listen.*.port

• Syntax: integer, port number
• Default: no default, this option is mandatory.
• Example: port = 5222

The port number to which the listening socket is bound.

listen.*.ip_address

• Syntax: string with the IP address
• Default: all-zeros address (e.g. "0.0.0.0" for IPv4)
• Example: ip_address = "127.0.0.1"

The IP address to which the listening socket is bound.

listen.*.proto

• Syntax: string, only "tcp" is accepted
• Default: "tcp"
• Example: proto = "tcp"

The protocol, which is TCP by default. Currently this is the only valid option.

listen.*.ip_version

• Syntax: integer, 4 or 6
• Default: if ip_address is specified, the IP version is determined from that address, otherwise it is 4
• Example: ip_version = 6

Allows to set the IP version to IPv6. Does not need to be set if ip_address is defined.

XMPP listener options

The options listed below can be set for the c2s, s2s and service listeners to adjust their parameters.

listen.*.backlog

• Syntax: positive integer
• Default: 1024
• Example: backlog = 1000

Overrides the default TCP backlog value.

listen.*.proxy_protocol

• Syntax: boolean
• Default: false
• Example: proxy_protocol = true

When set to true, Proxy Protocol is enabled and each connecting client has to provide a proxy header. Use only with a proxy (or a load balancer) to allow it to provide the connection details (including the source IP address) of the original client. Versions 1 and 2 of the protocol are supported.

listen.*.hibernate_after

• Syntax: non-negative integer or the string "infinity"
• Default: 0
• Example: hibernate_after = 10

Time in milliseconds after which a client process spawned by this listener will hibernate. Hibernation greatly reduces memory consumption of client processes, but may result in increased CPU consumption if a client is used very frequently. The default, recommended value of 0 means that the client processes will hibernate at every opportunity.

listen.*.max_stanza_size

• Syntax: positive integer or the string "infinity"
• Default: "infinity"
• Example: max_stanza_size = 10_000

Maximum allowed incoming stanza size in bytes.

Warning

This limit is checked after the input data parsing, so it does not apply to the input data size itself.

listen.*.num_acceptors

• Syntax: positive integer
• Default: 100
• Example: num_acceptors = 200

The number of processes accepting new connections on the listening socket.