[Pgpool-general] Number of connections and load balancing

[Joshua Berkus]

Tatsuo,

> > If I'm load-balancing between db1-4, it seems like I don't need to
> > have
> > a equal number of connections for each server.
> 
> As long as pgpool-II is not operated in replication mode, that will
> be
> true.  However you always need 100 proc in the master node. So I'm
> not
> sure that buys anything.

Well, that's pretty substantial for the remaining nodes.  Say you're load-balancing 400 read-only connections across 5 standbys.  I'd expect to do 80 connections each, not 400 connections each.  That's a huge difference in the number of connections per server, and the number of active processes on the pgpool server.   In that example, the difference is 2000 processes on the pgpool server vs. 400.  2000 processes is enough to degrade linux performance.

--Josh