[pgpool-hackers: 730] performance degrade?

[Tomonari Katsumata]

Hello

I'm trying simple performance test of pgpool using pgbench.
Then I noticed pgpool-3.4.0 has lower performance than 3.3.4.

I've changed some parameter in pgpool.conf a little
for adjusting to my environment.

--
listen_addresses = '*'
backend_port0 = 22934
backend_data_directory0 = '/home/katsumata/local/pgsql934/data
num_init_children = 20
--

Other parameters are used with default value in pgpool.conf.

The results are below.

------------------------------------------------------------
3.4.0
$ pgbench -p 9999 -c 10 -T 300 bench
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 10
number of threads: 1
duration: 300 s
number of transactions actually processed: 77189
tps = 256.613427 (including connections establishing)
tps = 256.701916 (excluding connections establishing)

------------------------------------------------------------
3.3.4
$ pgbench -p 9999 -c 10 -T 300 bench
starting vacuum...end.
transaction type: TPC-B (sort of)
scaling factor: 1
query mode: simple
number of clients: 10
number of threads: 1
duration: 300 s
number of transactions actually processed: 109285
tps = 364.264430 (including connections establishing)
tps = 364.515379 (excluding connections establishing)
------------------------------------------------------------

I set checkpoint_segments to 100, and before running
pgbench I execute CHECKPOINT to reduce its impact.

Am I missing some settings for good performance?

Another Information:
I'm using RPM packages, and the versions are below.
- pgpool-II-pg93-3.4.0-1.pgdg.x86_64.rpm
- pgpool-II-pg93-3.3.4-2.pgdg.x86_64.rpm

regards,
----------------
Tomonari Katsumata