[pgpool-general: 2481] Re: native replication PITR problems

Tatsuo Ishii ishii at postgresql.org
Fri Jan 24 07:47:12 JST 2014


Hi,

This week I am busy with working on my job. I just want to give a
short follow:

> Hi all, 
> 
> just some clarifications : 
> 
> 
> So, what I understand from here is that when I perform online recovery I 
> should stop the stand-by pgpool server. 

Yes.

> Also, on the primary server 
> there should be no connections open left, and until the recovery is 
> performed, no other connections will be opened.

Assuming you choose master/slave plus streaming replication mode,
no. The primary server can work as usual while performing the
recovery.

> The entire cluster will 
> be basically down when 2nd stage recovery process is running.
> Are these assumptions correct ?

Again if I can assume you choose master/slave plus streaming
replication mode, no.

First of all, you don't need to define 2nd stage recovery process. It
only needs for replication mode (replication_mode = on).

Also while doing recovery, pgpool-II happily accepts new connections
from clients and even executes DMLs, which will be sent to the primary
PostgreSQL. The modifications made to the database are recorded on the
WAL on the primary and will be forwarded to the standby which is being
recovered. Once the standby server boots up, it will replay the wal
log sent from the primary.

Best regards,
--
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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