pcp
[Top] [All Lists]

Re: PR1073 - pmlogger PID lifetime-matched logging

To: Lukas Berk <lberk@xxxxxxxxxx>
Subject: Re: PR1073 - pmlogger PID lifetime-matched logging
From: fche@xxxxxxxxxx (Frank Ch. Eigler)
Date: Thu, 26 Feb 2015 15:46:15 -0500
Cc: pcp@xxxxxxxxxxx, minnus@xxxxxxxxxxx, jpwhite4@xxxxxxxxxxx, tyearke@xxxxxxxxxxx
Delivered-to: pcp@xxxxxxxxxxx
In-reply-to: <87sids32ao.fsf@xxxxxxxxxx> (Lukas Berk's message of "Thu, 26 Feb 2015 14:23:11 -0500")
References: <87sids32ao.fsf@xxxxxxxxxx>
User-agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux)
Hi, Lukas -


> Please see commit 7347927a67849a74b67d8b25fb58c033ee79042d on
> git://sourceware.org/git/pcpfans.git lberk/dev

Thanks, nice work!  Included some Buffalo folks on cc:, because the
idea for this PR [1] came from their site needs at CCR, to have
job-specific pmlogger data.  It would be nice to know whether, with
this facility, a "pmlc one-shot METRIC" widget would be helpful or
redundant.


> Included is a proposed solution for PR1073, monitoring and matching
> the lifetime of a pmlogger instance to a PID specified.  I've also
> included qa and have found no regressions when testing the pmlogger
> qa group.  Any comments appreciated.

I'd suggest just a couple of things.  The man page should show that
the $pid in question must be related to the pmlogger process to the
degree that the kernel must permit a kill($pid,0) to it, which means
in effect that only one's own processes may be monitored.  Another
thing is the timing of the checking done in the pmlogger main loop: it
is done apprx. once per alarm-expiry, meaning no more frequently than
the normal metric-polling interval (60s default).  The test case looks
nice & simple (though the exact number of recorded entries, 4, might
oscillate to and fro on a busier test machine).  (A total tool-shed
nit would be to change "--PID" to "--pid".)


[1] http://oss.sgi.com/bugzilla/show_bug.cgi?id=1073


- FChE

<Prev in Thread] Current Thread [Next in Thread>