David Brain wrote:
> Hi,
>
> I have a working Slony environment, but I would really appreciate some
> assistance on tuning/configuration for better performance.
>
> My situation is that I have source servers (masters) replicating to
> one archive (slave) server - each of the source servers basically
> replicates one table (which has a unique name) to the archive server.
>
> The problem I am having is that there is a significant number of
> writes (maybe 20-60 rows per second) from each source server into the
> archive, and the large number of small writes is taking a toll on the
> archive server in terms of disk performance.
>
> Is there a way to configure the Slony such that the writes take place
> in a more 'batched' fashion, say writing all the rows from 10-15
> seconds worth of imports in 1 transaction.  In our situation there is
> no vital need for the archive server to be in tight sync with the
> source server - it could lag by as much as 5 mins without there being
> a significant problem.
>
The parameter that you'll want to change is "sync_interval".  It can be
set on the command line via the "-s" option.

The default value is likely 2000 (2000ms, or 2s); if you increase that,
you will reduce how often SYNCs get generated, which will have the
effect that you are looking for.

To increase the time covered to 15s, you'd run:

slon -s 15000 [and other parms, of course :-)]