[ClusterLabs] crm_mon memory leak

[Ken Gaillot]

On 10/30/2015 05:29 AM, Karthikeyan Ramasamy wrote:
> Dear Pacemaker support,
> We are using pacemaker1.1.10-14 to implement a service management framework, with high availability on the road-map.  This pacemaker version was available through redhat for our environments
> 
>   We are running into an issue where pacemaker causes a node to crash.  The last feature we integrated was SNMP notification.  While listing out the processes we found that crm_mon processes occupying 58GB of available 64GB, when the node crashed.  When we removed that feature, pacemaker was stable again.
> 
> Section 7.1 of the pacemaker document details that SNMP notification agent triggers a crm_mon process at regular intervals.  On checking clusterlabs for list of known issues, we found this crm_mon memory leak issue.  Although not related, we think that there is some problem with the crm_mon process.
> 
> http://clusterlabs.org/pipermail/users/2015-August/001084.html
> 
> Can you please let us know if there are issues with SNMP notification in Pacemaker or if there is anything that we could be wrong.  Also, any workarounds for this issue if available, would be very helpful for us.  Please help.
> 
> Thanks,
> Karthik.

Are you using ClusterMon with Pacemaker's built-in SNMP capability, or
an external script that generates the SNMP trap?

If you're using the built-in capability, that has to be explicitly
enabled when Pacemaker is compiled. Many distributions (including RHEL)
do not enable it. Run "crm_mon --help"; if it shows a "-S" option, you
have it enabled, otherwise not.

If you're using an external script to generate the SNMP trap, please
post it (with any sensitive info taken out of course).

The ClusterMon resource will generate a crm_mon at regular intervals,
but it should exit quickly. It sounds like it's not exiting at all,
which is why you see this problem.

If you have a RHEL subscription, you can open a support ticket with Red
Hat. Note that stonith must be enabled before Red Hat (and many other
vendors) will support a cluster. Also, you should be able to "yum
update" to a much newer version of Pacemaker to get bugfixes, if you're
using RHEL 6 or 7.

FYI, the latest upstream Pacemaker has a new feature that will be in
1.1.14, allowing it to call an external notification script without
needing a ClusterMon resource.