[ClusterLabs] Antw: Re: When the DC crmd is frozen, cluster decisions are delayed infinitely
kwenning at redhat.com
Thu Sep 8 06:31:01 EDT 2016
On 09/08/2016 11:51 AM, Shermal Fernando wrote:
> Hi Jehan-Guillaume,
> Sorry for disturbing you. This is really important for us to pass this test on the pacemaker resiliency and robustness.
> To my understanding, it's the pacemakerd who feeds the watchdog. If only the crmd is hung, fencing will not work. Am I correct here?
sbd is observing pacemaker (basically by interfering with corosync and
reading the cib - both
obviously not affected by your test-scenario) and is feeding the
watchdog if everything seems ok.
> Shermal Fernando
> -----Original Message-----
> From: Jehan-Guillaume de Rorthais [mailto:jgdr at dalibo.com]
> Sent: Thursday, September 08, 2016 3:12 PM
> To: Shermal Fernando
> Cc: Cluster Labs - All topics related to open-source clustering welcomed
> Subject: Re: [ClusterLabs] Antw: Re: When the DC crmd is frozen, cluster decisions are delayed infinitely
> On Thu, 8 Sep 2016 08:58:15 +0000
> Shermal Fernando <shermalfe at millenniumit.com> wrote:
>> Hi Jehan-Guillaume,
>> Does this means watchdog will serf-terminate the machine when the crm
>> daemon is frozen?
> This means that if the machine is under such a load that PAcemaker is not able to feed the watchdog, the watchdog will fence the machine itself.
>> -----Original Message-----
>> From: Jehan-Guillaume de Rorthais [mailto:jgdr at dalibo.com]
>> Sent: Thursday, September 08, 2016 12:52 PM
>> To: Digimer
>> Cc: Cluster Labs - All topics related to open-source clustering
>> Subject: Re: [ClusterLabs] Antw: Re: When the DC crmd is frozen,
>> cluster decisions are delayed infinitely
>> On Thu, 8 Sep 2016 15:55:50 +0900
>> Digimer <lists at alteeve.ca> wrote:
>>> On 08/09/16 03:47 PM, Ulrich Windl wrote:
>>>>>>> Shermal Fernando <shermalfe at millenniumit.com> schrieb am
>>>>>>> 08.09.2016 um
>>>>>>> 06:41 in
>>>> <8CE6E8D87F896546B9C65ED80D30A4336578CB4A at LG-SPMB-MBX02.lseg.stockex.local>:
>>>>> The whole cluster will fail if the DC (crm daemon) is frozen due
>>>>> to CPU starvation or hanging while trying to perform a IO operation.
>>>>> Please share some thoughts on this issue.
>>>> What is "the whole cluster will fail"? If the DC times out, some
>>>> recovery will take place.
>>> Yup. The starved node should be declared lost by corosync, the
>>> remaining nodes reform and if they're still quorate, the hung node
>>> should be fenced. Recovery occur and life goes on.
>> And fencing might either come from outside, or just from the server
>> itself using watchdog.
> This e-mail transmission (inclusive of any attachments) is strictly confidential and intended solely for the ordinary user of the e-mail address to which it was addressed. It may contain legally privileged and/or CONFIDENTIAL information. The unauthorized use, disclosure, distribution printing and/or copying of this e-mail or any information it contains is prohibited and could, in certain circumstances, constitute an offence. If you have received this e-mail in error or are not an intended recipient please inform the sender of the email and MillenniumIT immediately by return e-mail or telephone (+94-11) 2416000. We advise that in keeping with good computing practice, the recipient of this e-mail should ensure that it is virus free. We do not accept responsibility for any virus that may be transferred by way of this e-mail. E-mail may be susceptible to data corruption, interception and unauthorized amendment, and we do not accept liability for any such corruption, interceptio!
> n or amen
> dment or any consequences thereof. www.millenniumit.com
> Users mailing list: Users at clusterlabs.org
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
More information about the Users