Re: What causes streaming replication delay? [SOLVED, I think]

On Wed, 31 Aug 2016 16:22:22 -0400
Dianne Skoll <dfs@roaringpenguin.com> wrote:

> Hi,
>
> I think I solved it.  This is so ridiculous!
>
> The primary and standby databases are 200km apart and the path
> between them has a bandwidth of only 100 Mb/s.  We had bursts of
> writes that created huge amounts of replication traffic.  In addition
> to streaming replication, we're still copying WAL files over for
> safety (and also because this is 9.1...)
>
> We were hitting our bandwidth limit.
>
> By adding the --bwlimit parameter to the rsync command that copies
> the WAL files, we can limit the bandwidth usage during the bursts
> while still keeping it high enough for the WAL-file archiving to keep
> up on average.
>
> Keeping an eye on it for 24h before I completely declare it solved.

You were bitten by the RFC 1925 points 1, 2 and 9. A solution as is point 3 is "a bad idea".

https://tools.ietf.org/html/rfc1925

> Regards,
>
> Dianne.
>
>
> --
> Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-admin


---   ---
Eduardo Morras <emorrasg@yahoo.es>