[pgpool-general: 7505] Re: Problems with pg_rewind

[Emond Papegaaij]

> One possible reason I can think of that may be causing this problem is
> that our testcases require the creation of snapshots for the vms
> running the cluster. These snapshots are restored at the beginning of
> the test. We do make sure the cluster is in a consistent state before
> we continue with the test, but maybe some part of the cluster is still
> not entirely in sync. We've changed the re-synchronization code
> yesterday to fully stop and restart the entire cluster in a reliable
> way rather than trying to fix a distorted cluster. We haven't seen the
> error since, but it will require some more runs to be sure. It still
> is a strange issue, because even if it's caused the restoring the vm
> snapshots, all pgpools and postgresql databases have already been
> restarted prior to this failure.

Updating on this possible cause: We've observed the same failure with
our new setup. In this setup all pgpool and pg nodes are stopped and
restarted in a predictable way. This works great and restores the
cluster consistently in a healthy state. However, we still hit the
rewind problem.

Also, we've updated pgpool to the latest version, 4.2.2.

Best regards,
Emond