[ClusterLabs] பதில்: Re: crm_mon memory leak

[Ken Gaillot]

On 11/02/2015 09:39 AM, Karthikeyan Ramasamy wrote:
> Yes, Ken.  There were multiple instances of the external script also running.  What do you think could possibly be wrong with the script that triggers the crm_mon process everytime?

It's the other way around, crm_mon spawns the script. So if the script
doesn't exit properly, neither will crm_mon.

Easy test: put an "exit" at the top of your script. If the problem goes
away, then it's in the script somewhere. Mostly you want to make sure
the script completes within your monitoring interval.

> We are on RHEL 6.5.  I am not sure what's the plan for RHEL 6.7 and 7.1.  
> 
> Thanks,
> Karthik.
> 
> -----Original Message-----
> From: Ken Gaillot [mailto:kgaillot at redhat.com] 
> Sent: 02 நவம்பர் 2015 21:04
> To: Karthikeyan Ramasamy; users at clusterlabs.org
> Subject: Re: பதில்: Re: [ClusterLabs] crm_mon memory leak
> 
> On 10/31/2015 12:38 AM, Karthikeyan Ramasamy wrote:
>> Thanks, Mr.Gaillot.
>>
>> Yes, we trigger the snmp notification with an external script.  From your response, I understand that the issue wouldn't occur with 1.1.14, as it wouldn't require the crm_mon process.  Is this understanding correct?
> 
> Correct, crm_mon is not spawned with the new method. However if the problem originates in the external script, then it still might not work properly, but with the new method Pacemaker will kill it after a timeout.
> 
>> We have been given 1.1.10 as the supported version from RedHat.  If I raise a ticket to RedHat, would they be able to provide us a patch for 1.1.10?
> 
> If you're using RHEL 6.7, you should be able to simply "yum update" to get 1.1.12. If you're using RHEL 7.1, you should be able to get 1.1.13.
> That would give you more bugfixes, which may or may not help your issue.
> If you're using an older version, there may not be updates any longer.
> 
> If you open a ticket, support can help you isolate where the problem is.
> 
> When you saw many crm_mon processes running, did you also see many copies of the external script running?
> 
>> Many thanks for your response.
>>
>> Thanks,
>> Karthik.
>>
>>
>> ---- Ken Gaillot எழுதியது ----
>>
>> 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.
>