[PERFORM] Handling small inserts from many connections.

Hi team,

I'm trying to configure postgres and pgbouncer to handle many inserts from many connections.

Here's some details about what i want to achieve :

  We have more than 3000 client connections, and my server program forks backend process for each client connections.

  If backend processes send a request to its connected client, the client send some text data(about 3000 bytes) to the backend process and wait for

  next request.

  The backend process execute insert text data using PQexec from libpq lbirary, if PQexec is done, backend process send request to

  client again.

  All the inserts using one, same table.

The problem is, clients wait too long due to insert process is too slow.

It seems to working fine at first, but getting slows down after couple of hours,

each insert query takes 3000+ ms and keep growing.

Need some help to figure out an actual causes of this problem.

System information :

  PGBouncer 1.7.2.

  PostgreSQL 9.6.3 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-18), 64-bit on CentOS release 6.9 (Final).

  Kernel version 2.6.32-696.10.1.el6.x86_64

  Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz processor.