Hong Yuan wrote:

> Hello list,
>
> I have been using slony-1.0.5 for a simple one master one slave
> replication setup quite stably for some time with postgresql-7.4.7 on
> both sides.
>
> A week ago, I move the database to another machine and made the
> necessary modification to slon configuration and the system runs
> smoothly for a while. However, when today I checked the master node, I
> find a bunch of slon processes instead of one, which is the number I
> usually find.
>
> Is it normal for slon to start more than one processes for this
> setting? I don't think so, but what's the reason that suddenly so many
> processes come up? And more importantly, is my replication still
> running correctly now? Though sl_status indicates that there is no lag
> between the master and slave, I am still worring about the new phenomena.
>
> I started slon on the master node with:
>
> ws2:~# slon slontest "dbname=homelister host=localhost user=postgres"
> >master.log 2>&1 &
>
> And after that with 'ps -Af | grep slon', I got:
>
> ws2:~# ps -Af | grep slon
> root      6654  3121  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6656  6654  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6657  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6658  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6660  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6661  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6662  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6663  6656  0 12:56 pts/2    00:00:00 slon slontest
> dbname=homelister host=localhost user=postgres
> root      6851  4307  0 13:20 pts/7    00:00:00 grep slon
>
> How can I find out what is going on and whether any corrective
> measures are necessary?
>
> Thanks for assistance!
>
Is this on Linux?

On Linux, it is common for threads to be listed in the process table as
if they were processes.

slon is a multithreaded process, so it could, in that case, appear as
though it was being listed in the process table as many times as there
are threads + processes...