[Pgpool-general] pgbench hangs with pgpool II when count of connection is bigger than num_init_children

[Pavel Stehule]

Hello

I am testing pgpool II. I have small problem. If I understand to
documentation well, then pg_pool can create num_init_children *
max_pool connection. For default connection this is  128 connection.

But when I check pgbench with 33 connection, then pgbench hangs

number of clients: 30
number of transactions per client: 10
number of transactions actually processed: 300/300
tps = 127.959981 (including connections establishing)
tps = 129.241212 (excluding connections establishing)
[pavel at localhost etc]$ pgbench -c 32 -p 9999 postgres
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 32
number of transactions per client: 10
number of transactions actually processed: 320/320
tps = 173.632024 (including connections establishing)
tps = 175.622403 (excluding connections establishing)
[pavel at localhost etc]$ pgbench -c 33 -p 9999 postgres
starting vacuum...end.

why?

what is wrong on my expectation?

Regards
Pavel Stehule