Re: Laurenz Albe
> vacuumdb ... --analyze-in-stages --missing-stats-only
>
> processing hung, because the synchronous standby was not available and the transaction
> could not commit.
Interesting find, thanks for sharing.
> Yet I wonder if pg_upgradecluster could improve things by disabling synchronous_standby_names
> when the cluster ist started for the "finish" stage. I have attached a POC patch how this
> could be done. I didn't test it, and my Perl skills are marginal, but you get the idea.
That's also the command that does the final cluster start for
production, I wouldn't want such a change to persist.
Maybe we should instead change the analyze hook script to do that
internally? Setting PGOPTIONS should be enough:
PGOPTIONS="-csynchronous_commit=local"
> Perhaps this is too much black magic, not sure. But I wanted to share my experience.
There is already some code in pg_upgradecluster that works around
black magic problems:
# ensure we can upgrade DBs with default read-only transactions
$ENV{PGOPTIONS} .= " -cdefault_transaction_read_only=off";
This would just add one more wart of that kind.
Christoph
