On 01/18/2013 12:29 PM, Matthew Jurgens wrote: > Hi Andreas > > op5 sponsor the Check WMI Plus plugin > (http://edcint.co.nz/checkwmiplus/?q=donations_and_sponsorship). > Its a large perl plugin where the lack of embedded perl would approx double > the amount of CPU that it uses.
Actually, it's a large perl shim around a C binary called "wmic". Most of the time it uses is spent in network latency because there's no way the shim can get the compiled binary to do all its work for it in a single session. check_wmi is one of the (very many) plugins where embedded perl wouldn't improve things in any way what so ever, and the only way to get real performance out of it is to rewrite the wmic binary so that it can handle communication with the perl plugin, or so that wmic itself is turned into a plugin. Where embedded perl *does* matter is for perl plugins that utilize a large set of perl libraries. For those cases, embedded perl can cut execution time of plugins down to as much as 25% of the original cpu and I/O cost. However, the new worker model is still up to 12 times more efficient than the old one, so at best you're looking at a tiebreak for running perl plugins. > There are people using it so much (multiple tens of thousands of invocations > per day) that they already notice the amount of CPU that it consumes. > I'm sure they do, and patches to make language-specific workers work fine out of the box are ofcourse welcome, along with the code to make such workers fly. > I'm hoping the op5 can assist with a solution to the Nagios 4 problem of no > embedded Perl. It's not a problem that Nagios 4 has no embedded perl. It used to be a problem that Nagios 3 with embedded perl enabled leaked so much memory that the system became unusable after a day or two of running. This is (potentially) a performance issue caused by a single plugin being heavily used in spite of it being crap code that just wraps a second program. > Why has it been taken out anyway? For all the reasons stated above. > There are a lot of plugins out there that use Perl. > And for the most part it's still faster to run checks with Nagios 4 without embedded perl than it is to run checks with Nagios 3 with embedded perl compiled in and enabled. The only exception is where large and heavy plugins written in perl are extensively and almost exclusively used, and the perl loadtime dominates the time it takes for the plugin to run. That's not the case with check_wmi. For a workaround, you may want to look into mod_gearman. It's one of the unofficially blessed eventbroker modules that are known to work well with Nagios 4, and as a happy coincidence it still supports embedded perl. I know for a fact that Nagios 4 with mod_gearman works very well, and if you put your perl-based checks in a single service group and let mod_gearman handle only those, you'll have a system that can easily handle tens of thousands of checks without breaking a sweat. As a final note; Embedded perl *may* yet come back to Nagios. If it does, it will be as a multi-stage rocket that goes like this: 1. Make Nagios recognize different script languages. 2. Make Nagios' worker process manager capable of distributing checks based on scripting language. 3. Build a special-purpose worker that supports perl caching and whatnot and get it included in Nagios. Given that it's done properly and the code holds good quality, I'd be more than happy to take patches that implements script recognition and a perl-worker. Note that the worker will have to be able to handle the case when plugins can't be executed by it since they don't conform to whatever rules the embedded perl layer chucks up. It will, however, *never* be in the plain core worker, which is meant to be as stable and simple as possible. -- Andreas Ericsson andreas.erics...@op5.se OP5 AB www.op5.se Tel: +46 8-230225 Fax: +46 8-230231 Considering the successes of the wars on alcohol, poverty, drugs and terror, I think we should give some serious thought to declaring war on peace. ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
