[SAC] Re: projectsVM: rsync reniced to 10

Martin Spott Martin.Spott at mgras.net
Sat May 26 01:21:41 PDT 2012


Hi Tim,

On Thu, May 24, 2012 at 06:09:57PM -0600, Tim Schaub wrote:

> I've removed three uses of rsync in the script that updates the hosted
> OpenLayers sites.  I'm hoping this will alleviate future problems.  I
> see someone has added "nice" to our cron job.
> 
>     # m h  dom mon dow   command
>     33 * * * *  nice -n 18
> /osgeo/openlayers/repos/openlayers/tools/update_dev_dir.sh

....  and set it to an hourly schedule instead of running the "rsync"
job every minute.
As far as I can tell, the issue we faced was triggered by "rsync" jobs
accumulting, because every individual of them didn't finish within one
minute.  Maybe the remote end was almost unavailable or at least very
slow.  Thus, with every new "rsync" every minute, the remote end was
responding even slower than before, leading to a pile of pending
"rsync" jobs with no chance to recover.

I'd say it's ok to run a "touch ${HOME}/.crond-running" every minute,
but running an "rsync" job which highly depends on network latency as
well as on the availability and performance of the remote end is rude -
especially in a case when the maintainer of the respective job doesn't
monitor the primary communication channel for the ressources he's
using.

>From my perspective I'd recommend to leave things in the current state
and to check early for upcoming trouble.

Cheers,
	Martin.
-- 
 Unix _IS_ user friendly - it's just selective about who its friends are !
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