On 11/24/2004 5:57 PM, Christopher Browne wrote:

> We ran into the "obsolete sl_confirm" entries problem again today, as
> some entries lingering from a week or so ago lead to pretty stellar
> expansion of sl_log_1 and sl_seqlog...  

The whole thing is fixed in 1.0.5. Look at the top of the function 
cleanupEvent() in src/backend/slony1_funcs.sql.


Jan

> 
> I beefed up FAQ #17 as a result...
> <http://cbbrowne.dyndns.info:8741/cgi-bin/twiki/view/Sandbox/SlonyFAQ17>
> 
> The "clever" query that came up was thus:
> 
>   select * from @NAMESPACE at .sl_confirm where con_origin not in (select
>   no_id from @NAMESPACE at .sl_node) or con_received not in (select no_id
>   from @NAMESPACE at .sl_node);
> 
> I can see several directions to take this:
> 
>  1.  It would seem worthwhile to have a script that looks at node
>      configuration to find anomalies.
> 
>      One of my coworkers has starting drafting such a script...
> 
>  2.  Have slon run this query at startup time, and if it finds
>      entries, report the fact, and terminate itself.
> 
>  3.  Have slon run this query as part of the cleanup thread, and
>      automatically purge out the offending entries.
> 
> In any case, if a node were to be dropped and later recreated, I'd
> think the orphaned sl_confirm entries would be a Very Bad Thing,
> right?  Those entries could convince the node that it was synced to a
> later set of data than it was truly synced to, right?
> 
> The fact that 1.0.5 causes "drop node" to clean up after dropped nodes
> doesn't strike me as being quite good enough.  That means that nodes
> dropped in 1.0.5 are cleaned up after, but we evidently did some node
> dropping that preceded 1.0.5, and we can't guarantee that someone
> won't have such "sludge" around...


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