25.7.4. Using RELP

Reliable Event Logging Protocol (RELP) is a networking protocol for data logging in computer networks. It is designed to provide reliable delivery of event messages, which makes it useful in environments where message loss is not acceptable.
To configure RELP, first install the rsyslog-relp package both on the server and the client:
~]# yum install rsyslog-relp
Then, configure both the server and the client.
  1. To configure the client, configure:
    • loading the required modules
    • the TCP input port
    • the transport settings
    by adding the following configuration to the /etc/rsyslog.conf file:
    $ModLoad omrelp
    $ModLoad imuxsock
    $ModLoad imtcp
    $InputTCPServerRun "port"
    *.*  :omrelp:"target_IP":"target_port"
    Replace port to start a listener at the required port.
    Replace target_IP and target_port with the IP address and port that identify the target server.
  2. To configure the server:
    • configure loading the modules
    • configure the TCP input similarly to the client configuration
    • configure the rules and choose an action to be performed
    by adding the following configuration to the /etc/rsyslog.conf file:
    $ModLoad imuxsock
    $ModLoad imrelp
    $RuleSet relp
    *.*		 "log_path"
    $InputRELPServerBindRuleset relp
    $InputRELPServerRun "target_port"
    Replace target_port with the same value as on the clients.
    In the previous example, log_path specifies the path for storing messages.