After installed Pgpool with 2 postgresql nodes with streaming replication, I have noticed that access directly to postgresql is more efficient than through pgpool.
I supposed that load balance could increase the transactions per second executed because each node could receive more load, but the results shown below are not expected.
This is the setup:
Pgpool 3.6.1 whit connection pooling, streaming replication mode and load balancing mode.
2 PostgreSQL server 9.6.1 whit streaming replication.
For the tests I used sysbench and pgbench.
The results of sysbench:
Concurrent Users | 1 | 20 | 50 | 100 |
PostgreSQL (TPS) Direct | 1166 | 20936 | 25743 | 27344 |
Pgpool (TPS) | 2240 | 7628 | 7013 | 6135 |
The results of pgbench
| 1 | 20 | 50 | 100 |
PostgreSQL (TPS) Direct | 1403 | 6805 | 6194 | 5726 |
Pgpool (TPS) | 511 | 5430 | 5528 | 4705 |
As you can see in both cases even with load balance, the total transactions per second are lower.
Is this the expected behavior. Is there any way to allow more TPS when pgpool is used?
There are other publications with similar results:
https://www.os3.nl/_media/2011-2012/courses/lia/rory_breuk_gerrie_veerman_-_report.pdf (page 28)
http://www.mail-archive.com/pgpool-general@pgfoundry.org/msg03326.html
Regards
