On 04/18/2017 03:07 AM, Michael Paquier wrote:
> Hi all,
>
> Some of you may have noticed that hamster is heavily red on the
> buildfarm. I have done a bit of investigation, and I am able to
> reproduce the failure manually. But actually after looking at the logs
> the error has obviously showed up:
> 2017-04-16 05:07:19.650 JST [18282] LOG: database system is ready to
> accept connections
> 2017-04-16 05:08:36.725 JST [18296] LOG: using stale statistics
> instead of current ones because stats collector is not responding
> 2017-04-16 05:10:22.207 JST [18303] t/010_pg_basebackup.pl LOG:
> terminating walsender process due to replication timeout
> 2017-04-16 05:10:30.180 JST [18306] LOG: using stale statistics
> instead of current ones because stats collector is not responding
>
> Stale regressions means that the system is just constrained so much
> that things are timing out.
>
> In order to avoid such failures with normal regression tests, I have
> set up extra_config so as stats_temp_directory goes to a tmpfs to
> avoid stale statistics,
Yeah, but the way you have done it could also to lead to errors unless
you're very careful, as I found on axolotl (which died recently,
unfortunately). There I had to set the stats_temp directory to a
branch-specific name so a crash on branch A didn't leave stats picked up
by a run on branch B. I had a script that ran before every buildfarm run
that made sure the branch-specific directories existed on the tmpfs.
> but it is not possible to set up that with the
> TAP tests. I could always disable --enable-tap-tests on this machine
> but I don't think that this is a correct answer. Something that could
> be done is to use an environment variable to set up a base directory
> for all the nodes created in PostgresNode.pm, and use that for
> temporary statistics with a custom folder name. But that's not
> scalable if we want to enforce more parameter.
>
>
What more parameters do you want?
cheers
andrew
--
Andrew Dunstan https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
