[Pgpool-hackers] Proposal: failover control directive

[Tatsuo Ishii]

Hi pgpool hackers,

I would like to propose new directive to control failover behavior for
3.1.

Background:

Certain configration such as master/slave mode with Slony-I requires
master node not to failover. For this purpose the master node is
protected by HA(High Availability) software, it is desired for
pgpool-II disregard failover event on the master node.

Another use case is, D/W house like configuration with streaming
replication. Primary node is not often updated and standby servers are
used for load balancing. Sometimes it is not neccessary to promoto a
standby when the primary goes down, rather waiting for the primary
wakes up.

Proposal:
Add new directive to backend_*. to control the failover behavior.

backend_hostname0 = 'example.com'
backend_port0 = 5432
backend_weight0 = 1
backend_flag0 = 'flags' <--- proposed new directive

"flags" can be just a "allow failover or not" for now, but I would
like to allow to ORing several flags for the future porpose. At this
poing the flag would be:

ALLOW_TO_FAILOVER (allow to failover, default)
or
NEVER_FAILOVER (do not allow to failover)

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