Hi,    (Answering to my post)

I've just realized that for my 50 databases, there is no other solution 
than to setup 50 distinct slony clusters.

However, in my testbed, for one database and its replica (pgbench and 
pgbenchslave), I get 31 new
processes when I start the two "slon" commands (15 processes for 
"pgbench", and 16 for "pgbenchslave") :

Result of "ps ax" :
------------------------------------------------------------------------------------------------
26995 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
26997 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
26998 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
26999 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27000 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27001 ?        S      0:00 postgres: slony pgbench 127.0.0.1(3802) idle
27002 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27003 ?        S      0:00 postgres: slony pgbench 127.0.0.1(3803) idle
27004 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27005 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27006 pts/0    S+     0:00 slon slony_example dbname=pgbench user=slony 
host=localhost
27007 ?        S      0:00 postgres: slony pgbenchslave 127.0.0.1(3804) idle
27008 ?        S      0:00 postgres: slony pgbench 127.0.0.1(3805) idle
27009 ?        S      0:00 postgres: slony pgbench 127.0.0.1(3806) idle

27691 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27695 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27696 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27697 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27698 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27699 ?        S      0:00 postgres: slony pgbenchslave 127.0.0.1(4060) idle
27700 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27701 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27702 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27703 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27704 ?        S      0:00 postgres: slony pgbenchslave 127.0.0.1(4061) idle
27705 ?        S      0:00 postgres: slony pgbenchslave 127.0.0.1(4062) idle
27706 ?        S      0:00 postgres: slony pgbenchslave 127.0.0.1(4063) idle
27707 ?        S      0:00 postgres: slony pgbench 127.0.0.1(4064) idle
27708 pts/4    S+     0:00 slon slony_example dbname=pgbenchslave 
user=slony host=localhost
27709 ?        S      0:00 postgres: slony pgbench 127.0.0.1(4065) idle
------------------------------------------------------------------------------------------------

Why are there so many processes ? Is there a problem with my setup ?

If I multiply these 31 processes by 50 databases, the result is 1550 
processes for slony !!!!
And the memory usage will be overwhelming...


I'm looking for any advice.

Thank you in advance,
Philippe Ferreira.