6.15.2. Setting up Multicast Detection

Multicast detection uses JBoss's Remoting framework, which allows the agent to detect whenever a server comes on or goes off line within a few seconds. Using the Remoting framework requires support for multicast traffic; otherwise, the agent cannot detect the server. This has more configuration parameters than simple polling:
  • Setting to enable both server detection and multicast traffic (rhq.agent.server-auto-detection and rhq.communications.multicast-detector.enabled, respectively).
  • A wait interval between server communications (rhq.communications.multicast-detector.default-time-delay); if the server is silent longer than that interval, then the server is considered offline.
  • Await, or heartbeat, interval for the agent's own messages (rhq.communications.multicast-detector.heartbeat-time-delay). This value must be shorter than the JBoss ON server's heartbeat interval (rhq.communications.multicast-detector.default-time-delay), or it results in unnecessary messages and network traffic.
To enable multicast detection:
  1. Open the agent prompt. For example, if the agent process is already running, the prompt can be opened by re-running the rhq-agent.sh script with the -n option.
    agentRoot/rhq-agent/bin/rhq-agent.sh -n
  2. Send the setconfig with the multicast settings. The time-delay values are in milliseconds.
    > setconfig rhq.agent.server-auto-detection=true
    > setconfig rhq.communications.multicast-detector.enabled=true
    > setconfig rhq.communications.multicast-detector.default-time-delay=75000
    > setconfig rhq.communications.multicast-detector.heartbeat-time-delay=60000
  3. Restart the agent process to load the new configuration.
    agentRoot/rhq-agent/bin/rhq-agent-wrapper.sh stop
    
    agentRoot/rhq-agent/bin/rhq-agent.sh