[pgpool-general: 301] Re: Calculating num_init_children..?

[Lonni J Friedman]

On Mon, Mar 26, 2012 at 3:51 PM, Matt Wise <matt at nextdoor.com> wrote:
> In our environment we have 4 DB servers (db1/2/3/4) and db1 is the master. If we want to allow 512 total connections to each of our DB servers (so 2048 in total, among all 4 servers) ... whats the best tuning for pgpool's connection parameters. Assume we have 1 primary database, and 1 user that we connect to the database with.
>
> Do we want to do:
>  num_init_children = (512 * 4) = 2048
>  max_pool = 1
>
> Or when a client makes a connection, does PGPool simultaneously connect to all 4 DBs... and therefore we want:
>  num_init_children = 512
>  max_pool = 1
>

num_init_children is the number of connections that are opened to
*all* database servers specified in pgpool.conf.  If you set
num_init_children=2048, then you need to set max_connections=2048 in
postgresql.conf.

Based on your description above, I think what you want is to set
num_init_chidlren=512.