[pgpool-general: 2750] Re: pgpool builtin watchdog and order of the backend nodes

[Tatsuo Ishii]

[Back to to mailing list]
Please reply to the mailing list, rather than me...

If my understanding is correct, this looks like a "cascade" and
"circular" configuration.

            +--------------------+
            |                    |
            |                    v
postgres-1--+->postgres-2--+->PostgreSQL
^                          |
|                          |
+--------------------------+

What's the point of the configuration?

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

> It's very easy, the relevant part is here:
> 
> node postgres-2:
> -----------------------
> backend_hostname0 = 'localhost'
> backend_port0 = 5433
> backend_weight0 = 1
> backend_data_directory0 = '/var/lib/postgresql/9.3'
> backend_flag0 = 'ALLOW_TO_FAILOVER'
> 
> 
> backend_hostname1 = 'postgres-1'
> backend_port1 = 5433
> backend_weight1 = 1
> backend_data_directory1 = '/var/lib/postgresql/9.3'
> backend_flag1 = 'ALLOW_TO_FAILOVER'
> 
> node postgres-1:
> -----------------------
> backend_hostname0 = 'localhost'
> backend_port0 = 5433
> backend_weight0 = 1
> backend_data_directory0 = '/var/lib/postgresql/9.3'
> backend_flag0 = 'ALLOW_TO_FAILOVER'
> 
> 
> backend_hostname1 = 'postgres-2'
> backend_port1 = 5433
> backend_weight1 = 1
> backend_data_directory1 = '/var/lib/postgresql/9.3'
> backend_flag1 = 'ALLOW_TO_FAILOVER'
> 
> 
> 
> 2014-04-04 1:10 GMT+02:00 Tatsuo Ishii <ishii at postgresql.org>:
> 
>> I'm a little bit confused. Can you show your pgpool.conf?
>>
>> Best regards,
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
>>
>> > Hi!
>> >
>> > Just a simple question:
>> >
>> > Is the order of the nodes important for the pgpool cluster-members?
>> > I guess the answer is no, since only one pool member will be active at
>> any
>> > time, the only important is to enumerate all the backends for all the
>> pool
>> > members...
>> >
>> > But still I would like to know.
>> >
>> > Currently I use localhost as backend0 for all the nodes, and enumerate
>> all
>> > other backends in some order starting from backend1.
>> > The configs are generated from data tables (called pillars) by saltstack,
>> > currently I do not specify any order.
>> >
>> > The only strange thing is, that running pcp_node_info gives different
>> > result for the same node number on all members.
>> >
>> > Regards,
>> > Attila
>>