[chef] Re: Re: Re: Re: chef-client memory usage


Chronological Thread 
  • From: Jesse Nelson < >
  • To:
  • Subject: [chef] Re: Re: Re: Re: chef-client memory usage
  • Date: Thu, 8 Dec 2011 21:59:43 -0800

Manage the ammouny of data being shoved into your node object. This is typically where the memory is being consumed.  Disabling ohai plugins you don't use might help. 

Also pay attention to how your cookbooks are using search. Search results can get very large depending on node size and nodes returned.

On Dec 8, 2011 3:34 PM, "Brad Knowles" < "> > wrote:
On Dec 8, 2011, at 5:09 PM, Chris wrote:

> I agree with you, there are other problems surrounding our memory constraints. Namely, I'm not allowed to take memory away from Java and Java is never allowed to go into swap. We routinely provision 8GB VMs and give Java 7 of that, and the Java dev teams won't budge on that.

Ouch.  Yeah, politics is going to hurt.

> I'm really surprised that your client is so lean, but you're CentOS version is also newer then ours. We have systems ranging from 5.2-5.5, most have never been patched. I'm pretty sure we're missing out on some optimizations. I'm curious, are most of your cookbooks from Opscode or home grown?

We started with the Opscode cookbooks, but some of them have been modified pretty heavily, and we've created a few of our own.  Some of the cookbooks have come from elsewhere on github, with some local modifications.

I'm hoping that I will be able to get up to speed enough on git in the near future that we can contribute pretty much all our work back to github, so that the community can upgrade the Opscode cookbooks as appropriate, or the few non-Opscode cookbooks that we have used.  Most importantly, I think we may be the first non-Ubuntu site to make use of the edelight cookbook for MongoDB, and I'd really like to get our enhancements folded back in.

We've already signed all the CLA and CCLA forms, so now it's more a matter of me finding the time and inclination to "git" up to speed.



One other observation I'd like to make about VSS & RSS -- I think this might depend on your HyperVisor implementation, but I would be surprised if you didn't get "shared" pages with multiple different VMs on the system each with their own copy of chef-client that is running.

So, the real memory impact would not be the number of VMs times the VSS (as they claimed), but more like some cost-reduction factor times the number of VMs times the RSS for each of those chef-client instances.  The more VMs you've got on a single machine, I think the more memory overall that you would save as a result of getting something akin to deduplication being performed by the HyperVisor in conjunction with whatever OS is running in Ring Zero.  All they need to do is implement standard "copy-on-write" functionality for each of the affected pages.

--
Brad Knowles < "> >
SAGE Level IV, Chef Level 0.0.1



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