Re: terminating walsender process due to replication timeout

Hello,
Thank You for the response.

Yes that's possible to monitor replication delay. But my questions were
not about monitoring network issues.

I use exactly wal_sender_timeout=1s because it allows to detect
replication problems quickly.
So, I need clarification to the following questions:
Is it possible to use exactly this configuration and be sure that it will
be work properly.
What did I do wrong? Should I correct my configuration somehow?
Is this the same issue as mentioned here:
https://www.postgresql.org/message-id/e082a56a-fd95-a250-3bae-0fff93832510@2ndquadrant.com
? If it is so, why I do I face this problem again?

Thank you in advance.
Best regards,
Andrei

From: Rene Romero Benavides <rene(dot)romero(dot)b(at)gmail(dot)com>
To: AYahorau(at)ibagroup(dot)eu,
Cc: Postgres General <pgsql-general(at)postgresql(dot)org>
Date: 14/05/2019 20:12
Subject: Re: terminating walsender process due to replication
timeout

To detect network issues maybe you could monitor replication delay.

On Mon, May 13, 2019 at 6:42 AM <AYahorau(at)ibagroup(dot)eu> wrote:
Hello PostgreSQL Community!

I faced an issue on my linux machine using Postgres 11.3 .
I have 2 nodes in db cluster: master and standby.
I tried to perform a plenty of long-running queries which lead to the
databases desynchronization:
terminating walsender process due to replication timeout

Here is the output in debug mode:
2019-05-13 13:21:33 FET 00000 DEBUG: sending replication keepalive
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: StartTransaction(1) name: unnamed;
blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 DEBUG: CommitTransaction(1) name: unnamed;
blockState: END; state: INPROGRESS, xid/subid/cid: 0/1/0
2019-05-13 13:21:34 FET 00000 LOG: terminating walsender process due to
replication timeout

The issue is reproducible. I configure 2 nodes cluster, download
demo_small.zip from https://edu.postgrespro.ru/ and run the following
command:
psql -U user1 -f demo_small.sql db1
and I get the observed behaviour.

I know that I can increase wal_sender_timeout value to avoid this
behaviour (currently wal_sender_timeout is equal to 1 second.)
To be honest I don't want to increase wal_sender_timeout because I would
like to detect some network issues quickly.

After having googled I found that someone faced a similar issue
https://www.postgresql.org/message-id/e082a56a-fd95-a250-3bae-0fff93832510@2ndquadrant.com
which was fixed in PostgreSQL 9.4.16.

Is my issue the same as described here
https://www.postgresql.org/message-id/e082a56a-fd95-a250-3bae-0fff93832510@2ndquadrant.com
?
Is there any other chance to avoid it without increasing
wal_sender_timeout?

Thank you in advance.
Regards,
Andrei

--
El genio es 1% inspiración y 99% transpiración.
Thomas Alva Edison
http://pglearn.blogspot.mx/