Re: Monitoring Streaming Replication in 9.2

Hi,

Here<http://eulerto.blogspot.in/2011/11/understanding-wal-nomenclature.html>is
the blog which has good explanation about this.

If you want to find the lag in seconds, then you need to execute something
like below.

SELECT pg_last_xact_replay_timestamp() - now();

Regards,
Dinesh
manojadinesh.blogspot.com

On Fri, May 16, 2014 at 9:37 PM, J Adams <pacetownsley(at)gmail(dot)com> wrote:

>
> Newb question here. I have streaming replication working with 9.2 and I'm
> using Bucardo's check_postgres.pl to monitor replication. I see that it
> runs this query on the slave:
>
> SELECT pg_last_xlog_receive_location() AS receive,
> pg_last_xlog_replay_location() AS replay
>
> That returns hex, which is then converted to a number in the script.
>
> My question is this: what does that number represent? Is it just the log
> position? If so, how does the log position translate to queries? Does one
> log position = one query? (I did say this was a newb question.)
>
> How do I determine a meaningful alert threshold for that value? Is there a
> reliable way to monitor replication lag in seconds? How do other people
> handle this?
>
>