2.3. Clustering and High Availability

Utilizing CPG API for inter-node locking
Rgmanager includes a feature which enables it to utilize Corosync's Closed Process Group (CPG) API for inter-node locking. This feature is automatically enabled when Corosync's RRP feature is enabled. Corosync's RRP feature is considered fully supported. However, when used with the rest of the High-Availability Add-Ons, it is considered a Technology Preview.
Package: rgmanager-3.0.12.1-12
Support for redundant ring for standalone Corosync, BZ#722469
Red Hat Enterprise Linux 6.3 includes support for redundant ring with autorecovery feature as a Technology Preview. Refer to Section 3.7, “Clustering” for a list of known issues associated with this Technology Preview.
Package: corosync-1.4.1-7
corosync-cpgtool, BZ#688260
The corosync-cpgtool now specifies both interfaces in a dual ring configuration. This feature is a Technology Preview.
Package: corosync-1.4.1-7
Disabling rgmanager in /etc/cluster.conf, BZ#723925
As a consequence of converting the /etc/cluster.conf configuration file to be used by pacemaker, rgmanager must be disabled. The risk of not doing this is high; after a successful conversion, it would be possible to start rgmanager and pacemaker on the same host, managing the same resources.
Consequently, Red Hat Enterprise Linux 6 includes a feature (as a Technology Preview) that forces the following requirements:
  • rgmanager must refuse to start if it sees the <rm disabled="1"> flag in /etc/cluster.conf.
  • rgmanager must stop any resources and exit if the <rm disabled="1"> flag appears in /etc/cluster.conf during a reconfiguration.
Package: rgmanager-3.0.12.1-12
libqb package
The libqb package provides a library with the primary purpose of providing high performance client server reusable features, such as high performance logging, tracing, inter-process communication, and polling. This package is introduced as a dependency of the pacemaker package, and is considered a Technology Preview in Red Hat Enterprise Linux 6.3.
Package: libqb-0.9.0-2
pacemaker, BZ#456895
Pacemaker, a scalable high-availability cluster resource manager, is included in Red Hat Enterprise Linux 6 as a Technology Preview. Pacemaker is not fully integrated with the Red Hat cluster stack.
Package: pacemaker-1.1.7-6