Brian Hirt <bhirt at mobygames.com> writes:

> I've been testing switch overs on some of my development machines, and
> after I did a switch over and tried doing another switchover back, one
> of the slon processes died.  Now, when i try to restart that slon
> process, i get the following error:
>
> 	FATAL localListenThread: Another slon daemon is serving this
> node already
>
> After this message is displayed, nothing seem to happen to the slon
> process, and the only way i can kill it is with -9
>
> I've verified that there are no other slon processes accessing this
> node, and i've even restarted both master and slave databases (7.4.5
> and 8.0b3) I'm not sure how slony got in this state.  I'm running
> 1.0.2.  Any advice

This is item #4 in the "helpitsbroken.txt" file in the documentation
tree (which might not be included in 1.0.2, alas...)

=====================================================================

4.  After an immediate stop of postgresql (simulation of system crash)
in pg_catalog.pg_listener a tuple with
relname='_${cluster_name}_Restart' exists. slon doesn't start cause it
thinks another process is serving the cluster on this node.  What can
I do? The tuples can't be dropped from this relation.

The logs claim that "Another slon daemon is serving this node already"

It's handy to keep a slonik script like the following one around to
run in such cases:
================================================================================
twcsds004[/opt/twcsds004/OXRS/slony-scripts]$ cat restart_org.slonik 
cluster name = oxrsorg ;
node 1 admin conninfo = 'host=32.85.68.220 dbname=oxrsorg user=postgres port=5532';
node 2 admin conninfo = 'host=32.85.68.216 dbname=oxrsorg user=postgres port=5532';
node 3 admin conninfo = 'host=32.85.68.244 dbname=oxrsorg user=postgres port=5532';
node 4 admin conninfo = 'host=10.28.103.132 dbname=oxrsorg user=postgres port=5532';
restart node 1;
restart node 2;
restart node 3;
restart node 4;
================================================================================

'restart node n' cleans this stuff up so that you can restart the
node.

In version 1.0.3 and above, the startup process of slon looks for this
condition, and automatically cleans it up.

=====================================================================
-- 
"cbbrowne","@","ca.afilias.info"
<http://dev6.int.libertyrms.com/>
Christopher Browne
(416) 673-4124 (land)