[pgpool-hackers: 994] Proposal: connect to only neccessary DB nodes

[Tatsuo Ishii]

Here is a proposal for upcoming pgpool-II 3.5.

The problem:
Currently pgpool-II connects to all the DB nodes registered in
pgpool.conf when client session initiates. However this may cause
certain inconvenience, especially using CREATE DATABASE command under
master/slave mode (including streaming replication mode). Suppose
there are two DB nodes, 0 is primary and 1 is standby. If a user
issues CREATE DATABASE and exits the session, then connects to the
newly created database, pgpool-II could fail to connect to node 1
since the new database might not be created on node 1 yet.

Proposal:
In certain condition (I suppose load balancing is turned off), let
pgpool-II only connects to primary node only. This will avoid the
problem above since pgpool-II does not need to wait for newly created
database is ready once CREATE DATABASE is done.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp