Re: freeze cannot be finished

=?UTF-8?B?0JzQuNGI0LAg0KLRjtGA0LjQvQ==?= <tmihail(at)bk(dot)ru> writes:
> We are experiencing suspicious and very painful case in our top-business-critical database. We have only 7 weeks before emergency stop of the cluster cause wraparound task in autovacuum process can not be finished again and again.

I'm betting most of the pain comes from this:

> vacuum_cost_delay 40 (autovacuum_vacuum_cost_delay -1)
> vacuum_cost_limit 700

You've set these parameters to values that will make vacuum crawl.
It's not terribly surprising that it's failing to keep up with what
needs to be done.

I'd try setting vacuum_cost_delay to zero again until you're more
or less caught up. After that you could perhaps adopt a value in
the range of a millisecond or two. Not 40.

regards, tom lane