Re: replication lag despite corrective config

On Mon, 2018-11-19 at 17:46 -0800, Wyatt Alt wrote:
> I've been struggling to eliminate replication lag on a Postgres 9.6.6
> instance on Amazon RDS. I believe the lag is caused by early cleanup
> conflicts from vacuums on the master, because I can reliably resolve
> it by killing long-running queries on the standby. I most recently
> saw ten hours of lag on Saturday and addressed it this way.
>
> The standby is running with
> hot_standby_feedback = on
> max_standby_streaming_delay = 5min
> max_standby_archive_delay = 30s

With these settings, any conflicting query will be canceled after five
minutes. Perhaps your actual settings are different.

What do you get for

SELECT * FROM pg_settings WHERE name = 'max_standby_streaming_delay';

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com