Re: Auto-vacuum timing out and preventing connections

You can get the auto vacuum activity from pg_stat view. try to fond which table causes the timeout. and even more you csn disable autovacuum to check whether it still happens. 

---Original---
From: "David Johansen"<davejohansen(at)gmail(dot)com&gt;
Date: Sat, Jul 2, 2022 12:34 PM
To: "Andres Freund"<andres(at)anarazel(dot)de&gt;;
Cc: "pgsql-bugs"<pgsql-bugs(at)lists(dot)postgresql(dot)org&gt;;
Subject: Re: Auto-vacuum timing out and preventing connections

On Fri, Jul 1, 2022 at 9:11 PM Andres Freund <andres(at)anarazel(dot)de&gt; wrote:

Hi,

On 2022-06-27 14:38:21 -0600, David Johansen wrote:
&gt; We're running into an issue where the database can't be connected to. It
&gt; appears that the auto-vacuum is timing out and then that prevents new
&gt; connections from happening. This assumption is based on these logs showing
&gt; up in the logs:
&gt; WARNING:&nbsp; worker took too long to start; canceled
&gt; The log appears about every 5 minutes and eventually nothing can connect to
&gt; it and it has to be rebooted.

How many databases, tables and functions do you have?

1 database
427 tables
1 function
&nbsp;
&gt; What can we do to diagnose this problem and get our database working
&gt; reliably again?

Downthread you said you're on RDS - unfortunately you're going to have quite
limited access and are going to have to take it up with AWS.

Yes, I definitely understand that AWS will likely need to be involved or resolve this issue, but as I said previously, I'm trying to be proactive and just see what I could find.&nbsp;