Re: Keepalive for max_standby_delay - Mailing list pgsql-hackers

From Jim Nasby
Subject Re: Keepalive for max_standby_delay
Date
Msg-id 27D3E834-8064-4ECD-94A5-9C57C42D9F43@decibel.org
Whole thread Raw
In response to Re: Keepalive for max_standby_delay  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: Keepalive for max_standby_delay
List pgsql-hackers
On May 15, 2010, at 12:05 PM, Heikki Linnakangas wrote:
> What exactly is the user trying to monitor? If it's "how far behind is
> the standby", the difference between pg_current_xlog_insert_location()
> in the master and pg_last_xlog_replay_location() in the standby seems
> more robust and well-defined to me. It's a measure of XLOG location (ie.
> bytes) instead of time, but time is a complicated concept.

I can tell you that end users *will* want a time-based indication of how far behind we are. DBAs will understand "we're
thismany transactions behind", but managers and end users won't. Unless it's unreasonable to provide that info, we
shoulddo so. 
--
Jim C. Nasby, Database Architect                   jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net




pgsql-hackers by date:

Previous
From: "David E. Wheeler"
Date:
Subject: errcontext from PL/pgSQL (was message style for errcontext)
Next
From: Jim Nasby
Date:
Subject: Re: Partitioning/inherited tables vs FKs