Re: Streaming Recovery - Automated Monitoring

On Sun, Oct 3, 2010 at 07:07, Karl Denninger <karl(at)denninger(dot)net> wrote:
> Now how do I get an arithmetic difference between the two?  There will
> (usually) be a small difference between the master and slave on a busy
> system - what I want to do is query both and if the difference in their
> locations is greater than some defined size, start raising hell (e.g.
> sending SMS to people, etc)

Take a look at this code for an example:

http://munin-monitoring.org/browser/trunk/plugins/node.d/postgres_streaming_.in?rev=3905

I *think* it's complete :-)

> With Slony there was a set of system tables that would tell me how many
> unapplied changes were in the queue.  From this I could determine health -
> if the number was more than some reasonably-small amount, something was
> broken and alarms were to be raised.

Yeah, streaming can't do it quite so conveniently for you, since the
view can only talk to one database at a time.

--
 Magnus Hagander
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