Chapter 3. Clustering
Unfencing is done in resource cleanup only if relevant parameters changed
Previously, in a cluster that included a fence device that supports unfencing, such as
fence_scsi or fence_mpath, a general resource cleanup or a cleanup of any stonith resource would always result in unfencing, including a restart of all resources. Now, unfencing is only done if the parameters to the device that supports unfencing changed. (BZ#1427643)
pacemaker rebased to version 1.1.18
The pacemaker packages have been upgraded to upstream version 1.1.18, which includes the following behavioral difference:
Pacemaker now probes virtual machines launched with a Pacemaker Remote connection ("guest nodes"), just as it probes any node that joins the cluster. This allows Pacemaker to catch services that were mistakenly started at boot or by hand, and to refresh its knowledge after a resource clean-up. As such, it is important in order to be able to avoid having a service running in conflicting locations. However, these probes must be executed and the results processed before any resources can be started on the guest node. This can result in a noticeable increase in start-up time. Also, if users were previously relying on the probes not being done, the probes may fail (for example, if the relevant software isn't installed on the guest).
These effects can be avoided in cases where it is not possible for certain resources to run on the guest nodes. Usually there will already be -INFINITY location constraints enforcing that. Users can add
resource-discovery=never to the location constraint options to tell pacemaker not to probe that resource on the guest nodes. (This should not be done for any resource that can run on the guest.) (BZ#1513199)
clufter rebased to version 0.77.1
The clufter packages have been upgraded to upstream version 0.77.1, which provides a number of bug fixes, new features, and user experience enhancements over the previous version. Among the notable updates are the following:
- When producing
pcscommands, thecluftertool now supports a preferred ability to generatepcscommands that will update only the modifications made to a configuration by means of a differential update rather than a pushing a wholesale update of the entire configuration. Likewise when applicable, thecluftertool now supports instructing thepcstool to configure user permissions (ACLs). For this to work across the instances of various major versions of the document schemas,cluftergained the notion of internal on-demand format upgrades, mirroring the internal mechanics ofpacemaker. Similarly,clufteris now capable of configuring thebundlefeature. - In any script-like output sequence such as that produced with the
ccs2pcscmdandpcs2pcscmdfamilies ofcluftercommands, the intended shell interpreter is now emitted in a valid form, so that the respective commented line can be honored by the operating system. - When using
clufterto translate an existing configuration with thepcs2pcscmd-needlecommand in the case where thecorosync.confequivalent omits thecluster_nameoption (which is not the case with standard pcs-initiated configurations), the containedpcs cluster setupinvocation no longer causes cluster misconfiguration with the name of the first given node interpreted as the required cluster name specification. The same invocation will now include the--encryption 0|1switch when available, in order to reflect the original configuration accurately. - All
cluftercommands having a sequence ofpcscommands at the output, meaning they are passed through a post-processing to improve readability (unless disabled with--noop=cmd-wrap), no longer have the issue that some characters with special meaning in shell language were not being quoted, which changed their interpretation. - The
cluftertool now also covers some additional recently added means of configuration as facilitated withpcs(heuristics for a quorum device, meta attributes for top-levelbundleresource units) when producing the sequence of configuringpcscommands to reflect existing configurations when applicable. On thecorosyncconfiguration interfacing side, the format parser no longer misinterprets commented-out lines with spaces or tabulators in front of the respective delimiter, and support for some mechanically introduced options was reconsidered under closer examination of whatpcsactually handles.
For information on the capabilities of
clufter, see the clufter(1) man page or the output of the clufter -h command. For examples of clufter usage, see the following Red Hat Knowledgebase article: https://access.redhat.com/articles/2810031. (BZ#1526494, BZ#1381531, BZ#1517834, BZ#1552666)
