Re: How to reliably detect if it's a promoting standby

> What new public interfaces do you think are needed for 9.1 in this
> regard?

At this point I'm thinking of modifying existing pg_is_in_recovery(),
thus 0 new public interface. The heart of the function is
RecoveryInProgress(). It simply returns LocalRecoveryInProgress. In
addition to that, checking WalRcvData->walRcvsState being set to other
than WALRCV_RUNNING seems to solve the problem, though I have not
tested yet. Let me see if it's working...
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp

> Cheers,
> David.
> On Thu, Oct 14, 2010 at 11:10:14AM +0900, Tatsuo Ishii wrote:
>> Ok, it seems impossible to do that by using any public interfaces
>> currently available in PostgreSQL 9.0. I will create a custom C
>> function to be distributed along with pgpool-II.
>> --
>> Tatsuo Ishii
>> SRA OSS, Inc. Japan
>> English: http://www.sraoss.co.jp/index_en.php
>> Japanese: http://www.sraoss.co.jp
>>
>> > Hi,
>> >
>> > I'm looking for a way to reliably detect if it's a promoting
>> > standby. This is neccessary for pgpool-II manage streaming replication
>> > clusters. When primary goes down, standby *could* start promoting to
>> > primary. The only way to find it is calling
>> > pg_is_in_recovery(). Problem is, it returns true even if standby is
>> > promoting. If pgpool-II waits for cetain period, it may finishes
>> > promotion, thus it returns false. But how long should we wait?
>> >
>> > Any idea?
>> > --
>> > Tatsuo Ishii
>> > SRA OSS, Inc. Japan
>> > English: http://www.sraoss.co.jp/index_en.php
>> > Japanese: http://www.sraoss.co.jp
>> >
>> > --
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