JP Fletcher <jpfletch at ca.afilias.info> writes:
> I'm experimenting with logshipping (v.1.2.11) and am using, for the
> first time, the option in the slon conf file:
>
> command_on_logarchive
>
> I created a shell script that this command calls which applies syncs
> archives after they are written:
>
>   command_on_logarchive="/opt/clusters/cluster1_slony/archive/apply_archive.sh"
>
> My cluster has four nodes, not counting the log shipped replica, 8141,
> 8142, 8143, and 8194.  Node 8194 is the provider to the logshipped
> node, so I only configured 'command_on_logarchive' for the slon
> servicing this node, my assumption is that this is correct.  Nodes
> 8143, and 8141 are origins for sets.
>
> When I started things up, everything appeared to be fine.  The slon
> successfully applied 37 archives, each originating on either node 8141
> or 8143.  The 38th archive, however, and several subsequent archives
> originated on node 8142.  The slon made no attempt to apply these
> archives.  This left the archive counter  on 37.  The next archive the
> slon attempted to apply was from node 8143, and  expected the  archive
> counter to be on 48, which of course it was not, and everything went
> pear-shaped.   I have three questions:
>
> 1.  Should I have expected the command_on_logarchive option to work,
> and if so, did i do something wrong?

Hopefully apply_archive.sh looked something like:

#!/bin/sh
PGBINDIR=????
${PGBINDIR}/slony_logshipper $1

That might be hoped to work, although not quite right yet in 1.2.11
:-(.

> 2.  Why does the slon not try to apply archives from node8142?

slon shouldn't; I think you're meaning the slony_logshipper...

> 3.  Why are there archives from a node that is not active (no events
> should have originated on 8142, and no archive files exist for the
> other non-origin node)?

The node that isn't active should have very few, very infrequent,
archives that are devoid of actual content (beyond the headers).

It is expected that there *will* be some events coming from other
nodes, as every node does generate events, even if infrequently.

The behaviour will change a bit in 1.2.12; Jan just committed some
changes at the end of last week to fix up the handling of sequencing
of the archives, which turned out to be (sigh) troublesome.
-- 
select 'cbbrowne' || '@' || 'cbbrowne.com';
http://cbbrowne.com/info/
Rules of the Evil Overlord #79. "If my doomsday device happens to come
with  a reverse switch, as  soon as  it has  been employed  it will be
melted    down and  made  into   limited-edition commemorative coins."
<http://www.eviloverlord.com/>