[ClusterLabs] Pacemaker 1.1.16 - Release Candidate 1

[Klaus Wenninger]

On 11/03/2016 07:13 PM, Adam Spiers wrote:
> Klaus Wenninger <kwenning at redhat.com> wrote:
>> On 11/03/2016 05:28 PM, Adam Spiers wrote:
>>> Ken Gaillot <kgaillot at redhat.com> wrote:
>>>> ClusterLabs is happy to announce the first release candidate for
>>>> Pacemaker version 1.1.16. Source code is available at:
>>>>
>>>> https://github.com/ClusterLabs/pacemaker/releases/tag/Pacemaker-1.1.16-rc1
>>>>
>>>> The most significant enhancements in this release are:
>>> [snipped]
>>>
>>>> * Watchdog-based fencing using sbd now works on remote nodes.
>>> What were the problems with this before, exactly?  Thanks!
>> If you enabled just cluster-watcher on remote-nodes that
>> was not much of an observation.
>>
>> But if you in addition enabled pacemaker-watcher then
>> when the remote-node-resource switched from one
>> cluster-node to another the client receiving the
>> cib inside pacemaker-watcher didn't get that switch
>> and still insisted on getting something via the old
>> connection so that the node was reset via watchdog.
>>
>> Introducing a tcp-timeout derived from the
>> sbd-watchdog-timeout makes the connection timeout
>> and the client switches to the new control-node.
>>
>> So a remote-node would just be watchdog-fenced
>> if the remote-node-resource doesn't reconnect within
>> time - regardless which node it is running now.
>>
>> Actually that commit in pacemaker should be beneficial
>> for tooling run on remote-nodes - via proxy - in general.
> Thanks a lot for this info!  I have to admit I don't fully understand,
> because I don't know what pacemaker-watcher and cluster-watcher are.
> Are they specific to Red Hat?

No, nothing specific to Red Hat.
sbd consists of a couple of processes talking to each other.
One is the 'inquisitor' (opening the watchdog-device and
kicking it if everything seems OK) and there are multiple
'watchers' for the respective instances like pacemaker
(well the name says it), cluster (either exchanging cpg-messages
with corosync or checking for the existence of pacemaker_remoted)
and of course the watcher for the block-device (Red Hat
specific in that way that it is disabled in the build ;-) ).

>
> _______________________________________________
> Users mailing list: Users at clusterlabs.org
> http://clusterlabs.org/mailman/listinfo/users
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org