[Pgpool-hackers] Proposal: failover control directive

[Tatsuo Ishii]

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

> It seems there's no objection for this.  I am going to add
> documentatins, pool_status changes and commit them.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
> 
>>> 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?
>> 
>> Ok, I have created patches for this.
>> 
>> - Add new directive. If backend_flag0 = 'DISALLOW_TO_FAILOVER'(for
>>   example) is specified, no failover (including health checking,
>>   connection errors, pcp_detach_node) will happen. If you want to
>>   allow failover you can specify backend_flag0 =
>>   'ALLOW_TO_FAILOVER'. For backward compatibility sake, if
>>   backend_flag0 directive is omitted, it is regarded as backend_flag0
>>   = 'ALLOW_TO_FAILOVER' is specified.
>> 
>> - the directive can only be changed at pgpool starting up.
>> 
>> - No pool_status patches are included (yet).
>> 
>> - No documentation patches are included (yet).
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
> _______________________________________________
> Pgpool-hackers mailing list
> Pgpool-hackers at pgfoundry.org
> http://pgfoundry.org/mailman/listinfo/pgpool-hackers