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# RELP Input Module

Module Name: imrelp

Author: Rainer Gerhards

Description:

Provides the ability to receive syslog messages via the reliable RELP protocol. This module requires librelp to be present on the system. From the user's point of view, imrelp works much like imtcp or imgssapi, except that no message loss can occur. Please note that with the currently supported relp protocol version, a minor message duplication may occur if a network connection between the relp client and relp server breaks after the client could successfully send some messages but the server could not acknowledge them. The window of opportunity is very slim, but in theory this is possible. Future versions of RELP will prevent this. Please also note that rsyslogd may lose a few messages if rsyslog is shutdown while a network conneciton to the server is broken and could not yet be recovered. Future version of RELP support in rsyslog will prevent that. Please note that both scenarios also exists with plain tcp syslog. RELP, even with the small nits outlined above, is a much more reliable solution than plain tcp syslog and so it is highly suggested to use RELP instead of plain tcp. Clients send messages to the RELP server via omrelp.

Configuration Directives:

- Port <port>
  Starts a RELP server on selected port

Caveats/Known Bugs:

- ruleset can only be bound via legacy configuration format
- To obtain the remote system's IP address, you need to have at least librelp 1.0.0 installed. Versions below it return the hostname instead of the IP address.
- Contrary to other inputs, the ruleset can only be bound to all listeners, not specific ones. This is due to a currently existing limitation in librelp.

Sample:

This sets up a RELP server on port 20514.

module(load="imrelp") # needs to be done just once input(type="imrelp" port="20514")

Legacy Configuration Directives:

- InputRELPServerBindRuleset <name> (available in 6.3.6+) Binds the specified ruleset to all RELP listeners.
- InputRELPServerRun <port>
  equivalent to: Port

Caveats/Known Bugs:

- see description
- To obtain the remote system's IP address, you need to have at least librelp 1.0.0 installed. Versions below it return the hostname instead of the IP address.
- Contrary to other inputs, the ruleset can only be bound to all listeners, not specific ones. This is due to a currently existing limitation in librelp.

Sample:

This sets up a RELP server on port 20514.

$ModLoad imrelp # needs to be done just once $InputRELPServerRun 20514

[rsyslog.conf overview] [manual index] [rsyslog site]

This documentation is part of the rsyslog project.
Copyright © 2008-2011 by Rainer Gerhards and Adiscon. Released under the GNU GPL version 3 or higher.