Hello,
While trying to troubleshoot performance issues on our NFS server, it
became apparent that we have a peak of requests durings hours 0-3 every
day. This is currently hard to properly manage and results in slower
performance for everybody.
Here's a breakdown of the number of cronjobs scheduled to start in the
new SGE cluster, per hour:
473 * # hourly
213 0
106 1
82 2
78 3
54 9
50 4
48 7
45 12
42 5
You can see that, apart from hourly jobs, we have most cronjobs
starting in hours 1-3.
My advice is that, if your workload permits, *schedule your cronjobs
outside of that time window so you are not competing for resources with
everybody else*. The more spread throughout the day your cronjobs are,
the better.
Also beware of step values like "*/2" which will make your cronjob run
on hours 0 and 2 too.
If you have any questions, please find us on #wikimedia-cloud
Regards,
--
Giovanni Tirloni
Operations Engineer
Wikimedia Foundation