Cluster Messages

This section is a reference for all the messages sent within Aeron Cluster, which are defined in aeron-cluster-codecs.xml. This is based on v1.47.0 (the file hadn't changed for 2 years, but I've just spotted a small update - typical!).

Most are for messages, but some definitions below are for the format within snapshots. Note that some messages are used on more than one stream, e.g. SessionMessageHeader.

• Ingress

  ---

  • AdminRequest
  • ChallengeResponse
  • SessionCloseRequest
  • SessionConnectRequest
  • SessionKeepAlive
  • SessionMessageHeader

• Consensus

  ---

  • AppendPosition
  • BackupQuery
  • BackupResponse
  • CanvassPosition
  • CatchupPosition
  • Challenge
  • ChallengeResponse
  • CommitPosition
  • HeartbeatRequest
  • HeartbeatResponse
  • NewLeadershipTerm
  • RequestVote
  • StandbySnapshot
  • StopCatchup
  • TerminationAck
  • TerminationPosition
  • Vote

• Log

  ---

  • ClusterActionRequest
  • NewLeadershipTermEvent
  • SessionCloseEvent
  • SessionMessageHeader
  • SessionOpenEvent
  • TimerEvent

• Consensus Module

  ---

  • CancelTimer
  • CloseSession
  • ClusterMembersQuery
  • ScheduleTimer
  • ServiceAck
  • SessionMessageHeader

• Service

  ---

  • ClusterMembersExtendedResponse
  • ClusterMembersResponse
  • JoinLog
  • requestServiceAck
  • ServiceTerminationPosition

• Egress

  ---

  • AdminResponse
  • Challenge
  • NewLeaderEvent
  • SessionMessageHeader
  • SessionEvent

• Snapshot (Consensus Module)

  ---

  • ClusterSession
  • ConsensusModule
  • PendingMessageTracker
  • SnapshotMarker
  • Timer

• Snapshot (Clustered Service)

  ---

  • ClientSession
  • SnapshotMarker

Deprecated

Aeron Cluster requires each member to remain on the same host. It used to support 'dynamic join', where cluster members could be added while the cluster is running, but this was removed in version 1.41.0 (PR)

• AddPassiveMember
• ClusterMembers
• ClusterMembersChange
• JoinCluster
• MembershipChangeEvent
• RemoveMember
• SnapshotRecordingQuery
• SnapshotRecordings