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This web page is no longer maintained. Information presented here exists only to avoid breaking historical links.
The Project stays maintained, and lives on: see the Linux-HA Reference Documentation.
To get rid of this notice, you may want to browse the old wiki instead.

1 February 2010 Hearbeat 3.0.2 released see the Release Notes

18 January 2009 Pacemaker 1.0.7 released see the Release Notes

16 November 2009 LINBIT new Heartbeat Steward see the Announcement

Last site update:
2017-12-12 22:06:45

Consensus Cluster Membership (CCM) Module

The Consensus Cluster Membership module was originally created by RamPai, and is designed to provide subscribers with information about sets of FullyConnected nodes in the current cluster partition.

This information includes new additions to the membership, lost nodes, loss of quorum. It can deliver this information using either the SAF API or a an early draft of the OCF membership API (the latter API is more commonly used in the project, but the other should also work).

It is the middle "membership" layer that sits between Heartbeat (a messaging/infrastructure layer) and the new ClusterResourceManager (a resource allocation layer).

Using an enahanced version of an early draft of the OCF membership API, it now provides all of the following node information during events published to subscribers:

  • Node Id      (int)   : An int index for the node

  • Node UUID    (char*) : A 128-bit guaranteed unique identifier for the node.

  • Node Born on (int)   : The cluster's generation counter at the time this node joined.

  • Node uname   (char*) : The Nodes hostname as determined by uname -n

The last two are used as part of the DesignatedCoordinator's election process.

The order of the list of nodes given is consistent for every member in the partition.