[Pacemaker] staggered resource startup

Andrew Beekhof andrew at beekhof.net
Wed Sep 4 04:33:19 UTC 2013


On 04/09/2013, at 1:01 AM, Matthew O'Connor <matt at ecsorl.com> wrote:

> 
> On 08/27/2013 06:18 PM, Andrew Beekhof wrote:
> > Are you aware of this cluster
>       option?
> 
> 
>       >
> 
> 
>       >        batch-limit = integer [30]
> 
> 
>       >            The number of jobs that the TE is allowed to
>       execute in parallel
> 
> 
>       >
> 
> 
>       >            The "correct" value will depend on the speed and
>       load of your network and cluster nodes.
> 
> 
>       >
> 
> 
>       > As long as the VMs are truly started before the resource
>       agent reports "done", then lowering this value should spread the
>       load out more.
> 
> 
>       >
> 
> 
>       > There is also the possibility to specify ordering constraints
>       with kind=Serialize:
> 
> 
>       >
> 
> 
>       >   
> 
> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-crmsh/html/Pacemaker_Explained/s-resource-ordering.html
> 
> No, I was not aware of this option.  The catch to the batch-limit will be with the resource agent, as you said.  AFAIK this particular resource agent reports that a VM is started once libvirt reports it's started, though "started" and "booted" are very different states and libvirt does not care about whether or not the VM successfully booted.  The load I'm trying to limit occurs after the VM is started, i.e. while it's booting.  So, I'm thinking to get what I want, I will need to use the batch-limit in conjunction with a modified resource agent that will delay reporting success until some timeout has been reached.  Ick...but better than nothing! :)

A case could be made that the upstream agent should, perhaps optionally, wait for the VM to be booted before reporting success as well.
If you can make the change generic enough, I'd encourage you to submit it for inclusion.

> 
> Thanks for the info!
> -- Matthew
> 
> 
> -- 
> Thank you!
>   Matthew O'Connor
>   (GPG Key ID: 55F981C4)
> 
> 
> CONFIDENTIAL NOTICE: The information contained in this electronic message is legally privileged, confidential and exempt from disclosure under applicable law. It is intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender immediately by return e-mail and delete the original message and any copies of it from your computer system. Thank you.
>  
> EXPORT CONTROL WARNING:  This document may contain technical data that is subject to the International Traffic in Arms Regulations (ITAR) controls and may not be exported or otherwise disclosed to any foreign person or firm, whether in the US or abroad, without first complying with all requirements of the ITAR, 22 CFR 120-130, including the requirement for obtaining an export license if applicable. In addition, this document may contain technology that is subject to the Export Administration Regulations (EAR) and may not be exported or otherwise disclosed to any non-U.S. person, whether in the US or abroad, without first complying with all requirements of the EAR, 15 CFR 730-774, including the requirement for obtaining an export license if applicable. Violation of these export laws is subject to severe criminal penalties.
> 
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> 
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 841 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <https://lists.clusterlabs.org/pipermail/pacemaker/attachments/20130904/8734007b/attachment-0004.sig>


More information about the Pacemaker mailing list