Features/Cluster

It has been requested that this page be deleted.
Except for pacemaker inclusion, this Feature page is just a repeat of the cluster capabilities in Fedora 11 and is not needed.

Cluster

Summary

This is a significant update to the clustering stack - both for high availability and load balancing.

Owner

• Name: LonHohberger
• email: lhh@redhat.com
• Name: FabioMassimoDiNitto
• email: fabbione@redhat.com

Current status

• Targeted release: Fedora 42
• Last updated: 24 Jan 2012
• Percentage of completion: 70%

Detailed Description

Upstream has been developing the new version of the stack. The major features are:

• Improved quorum subsystem which is integrated in to the Corosync Cluster Engine (95% complete)
• A new command-line interface for administration of both the Corosync Cluster Engine and the Pacemaker Cluster Resource Manager (50% complete)
• Convergence on a single set of resource agents from the Linux clustering community
• Enhanced fencing support in the Pacemaker Cluster Resource Manager
• Separation of GFS2-specific utilities in to a separate project.

Note that this transition includes deprecations:

• CMAN will no longer provide quorum. Instead, this functionality is now part of Corosync
• Removal of the obsolete 'rgmanager' package. All users are advised to use Pacemaker for their failover needs.

Benefit to Fedora

The increased reliability and versatility of the cluster components included in Fedora 17 allow administrators to deploy Fedora in environments where greater availability and clustered file systems are required. Removal of rgmanager matches the capabilities offered by several other Linux distributions and allows the Fedora community to consort efforts on a single failover stack.

Dependencies

• corosync (2.0)
• pacemaker
• cluster-glue
• dlm (in review)

All packagers and upstreams have been informed upfront and worked together to achieve this goal.

Contingency Plan

None necessary

Documentation

• Clusters from Scratch
• Corosync FAQ

Release Notes

In addition to the cluster features present in Fedora 11, Fedora 12 includes the following enhancements:

• The update to version 1.0 (flatiron) of the Corosync Cluster Engine offers (on top of Fedora 11's features):
  • Plugin ABI & API stability guarantees for the duration of Corosync 1.0's lifetime
  • High performance, cluster-wide messaging
  • Ultra-high performance IPC subsystem available to other components and developers
  • Rolling upgrade compatibility with 0.80.z releases of OpenAIS
• The update to version 3.0 of the Linux-Cluster Project offers:
  • Reduced code and operational complexity compared to version 2 leading to greater reliability
  • Pluggable, simplified configuration management framework with plugins for XML and LDAP (experimental), including schemas for both classes
  • Improved code quality due to stricter coding guidelines
• The inclusion of pacemaker 1.0 offers (note: packages awaiting reviews):
  • Improved resource & failover management over rgmanager
    • Resource-dependency model allows for flexible placement of cluster resources
    • Can run rgmanager's resource agents with minimal changes, offering an upgrade path for users of rgmanager
  • Fine-grained resource management: administrators may operate on one resource instead of operating at the resource group level

Comments and Discussion

• See Talk:Features/Cluster