[Pgpool-general] Several questions about pgpool

[Michael Ulitskiy]

Hello,

I'm using pgpool 3.1 and recently discovered several things that
I'm not sure whether they're bugs or intended. I'd appreciate if someone
can enlighten me on that.
1. Will pgpool fork additional children when the number of available children exhausted? 
I was under impression it will, but the testing shows otherwise. Connecting clients just block
until another client disconnects and pgpool process becomes available.
2. I thought that each pgpool process can serve "max_pool" number of usernames, multiplexing
queries from different usernames. My testing shows it doesn't work. I set 
num_init_children=4
max_pool=4
So i expect to be able to connect 16 clients using 4 different usernames, but after 4 clients
connected (with different usernames) the 5th blocks waiting for available pgpool process.
Is my understanding wrong? What is the purpose of max_pool parameter then?
3. I'm using load-balancing mode with replication done by slony-I. It seems when a client
is connected, pgpool child opens connections to both primary and secondary backend
which means that the number of concurrently served clients do not depend on the number
of backends, right? In other words if I have num_init_children=32 then I won't be able to
connect more than 32 clients regardless of number of backends I'm using?
4. This is more a feature request. Have no idea how hard it is to do and whether it's possible
in pgpool architecture. I'm expecting to have hundreds of clients connecting through pgpool
to database cluster behind it. Some connections will be short-lived - several seconds, 
while others will be relatively long-lived - minutes-to-hours, while others will be permanent - daemons.
It would be really nice if pgpool children could process more than one connection multiplexing
queries from different connection. Is it possible?

Thanks,
Michael