On Tuesday, June 19, 2012 5:23:42 AM UTC-5, Duncan wrote: > > Hi folks, I'm scratching my head with a problem with system load. > > When Puppet checks in every hour, runs through all our checks, then exits > having confirmed that everything is indeed as expected, the vast majority > of the time no changes are made. But we still load our systems with this > work every hour just to make sure. Our current configuration isn't perhaps > the most streamlined, taking 5 minutes for a run. > > The nature of our system, however, is highly virtualised with hundreds of > servers running on a handful of physical hosts. It got me thinking about > how to reduce the system load of Puppet runs as much as possible. > Especially when there may be a move to outsource to virtualisation hosts > who charge per CPU usage (but that's a business decision, not mine). > > Is there a prescribed method for reducing Puppet runs to only be done when > necessary? Running an md5sum comparison on a file every hour isn't much > CPU work, but can it be configured so that Puppet runs are triggered by > file changes? I know inotify can help me here, but I was wondering if > there's anything already built-in? >
You seem to be asking whether there's a way to make the Puppet agent run to see whether it should run. Both "no, obviously not" and "yes, it's automatic" can be construed as correct answers. In a broader context, anything you run to perform the kind of monitoring you suggest will consume CPU. You'd have to test to see whether there was a net improvement. Consider also that although file checksumming is one of the more expensive operations Puppet performs, files are not the only managed resources in most Puppet setups. You'll need to evaluate whether it meets your needs to manage anything only when some file changes. There are things you can do to reduce Puppet's CPU usage, however. Here are some of them: - You can lengthen the interval between runs (more than you already have done). - You can apply a lighter-weight file checksum method (md5lite or even mtime). - You can employ schedules to reduce the frequency at which less important resources are managed. - You can minimize the number of resources managed on each node. John -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. To view this discussion on the web visit https://groups.google.com/d/msg/puppet-users/-/5UkHTsXNKIsJ. To post to this group, send email to puppet-users@googlegroups.com. To unsubscribe from this group, send email to puppet-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/puppet-users?hl=en.
