> On Tuesday 19 July 2005 08:04, Hannu Krosing wrote:
>> can I downgrade slony 1.1 to slony 1.0.5 just by installing the 1.0.5
>> and running "update functions"
>
> That is a process I have never tried, my gut tells me that the only way to
> downgrade is to uninstall node(s) and redo the whole shebang.

Actually, I can't think of a specific reason why it wouldn't be possible.
The use of data structures hasn't changed in any material way.

I'd certainly want to test it before trying it "for real," but I don't
remember anything making it downright implausible.

>> I'm getting massive lock contention on pg_listener on some busy
>> databases.
>
> Can you provide a bit more detail on this ?  if this is a problem I'd like
> to
> see this resolved properly as 1.1 should be an improvement all the way
> around.

That's an interesting claim, indeed.

I can't think of a reason for 1.1 to be way more aggressive at grabbing
locks on pg_listener than 1.0.5.

The only thing that comes to mind is the "adaptive grouping," where, if
things are running behind, things start with fairly small groups of SYNCs
and work their way up.  That would lead to there being somewhat more
events generated on subscriber nodes.  On the other hand, the smaller
grouping should mean that locks are applied for shorter periods of time,
which should make that more or less a "wash."

I'd be very interested in hearing how changes in 1.1 lead to "massive lock
contention" that didn't take place in 1.0.5.