Subject: bug#43850: cuirass: inconsistent SQL queries execution time.

From: Ludovic Courtès <[email-masked]>
Date: Mon, 26 Oct 2020 23:59:51 +0100

Hi,

Mathieu Othacehe <[email-masked]> skribis:

>> I have now copied the database to a tmpfs mounted directory to make sure
>> that those inconsistent duration are only caused by the I/O pressure on
>> berlin.
>
> This helps a lot. The Cuirass web service has been running smooth since
> two days, without any inconsistent query times.

Interesting.

> I'm considering using a tmpfs backed database for good. The problem is
> that we would need a save/restore mechanism in case Berlin
> reboots.

Hmm sounds risky, no?

I wonder if we could instead ensure no I/O-intensive workload runs that
machine.  I’m thinking in particular of the derivations that produce
ISO/qcow images that are not offloaded but maybe should.

WDYT?  Do you think that’d be enough?  Or is tmpfs our only hope?

Thanks,
Ludo’.