[pgpool-general: 1401] Re: pgPool Online Recovery Streaming Replication
ishii at postgresql.org
Sun Feb 17 17:13:26 JST 2013
> Hi all,
> I have the following question regarding the recovery of a filed Primary
> Database Server.
> Question 1: in the documentation, under Streaming Replication Online
> Recovery section.
> in steps 6:
> 1. After completing online recovery, pgpool-II will start PostgreSQL on
> the standby node. Install the script for this purpose on each DB
> nodes. Sample
> script <http://www.pgpool.net/docs/latest/pgpool_remote_start> is
> included in "sample" directory of the source code. This script uses ssh.
> You need to allow recovery_user to login from the primary node to the
> standby node without being asked password.
> To my understanding, i think the postgreSQL doesn't not need to be online
> for the recovery process right? Since later on it mentions that
> pgpool_remote_start will start up the DB on the failed node.
Acually standby PostgreSQL node should not be started.
> Question 2: in my configuration, i have 2 pgpool server with two backends.
> Will it work for oneline recovery?
Yes, but online recovery process should be initiated by one of pgpool,
not both. If you enable pgpool-II 3.2's watchdog, it will take care of
> Question 3: when the failed node comes back online, should i use
> pcp_recovery from DB primary or should i use pcp_attach on the failed node
> to recover the failed system? Actually in my case, both methods do not
> recover my system every time.
I'm confused. Didn't you start the online recovery process by using
pcp_recovery_node?(of course you could do it via pgpoolAdmin).
Anyway pcp_recovery_node automatically attach recovered node, and you
don't need to execute pcp_attach_node.
I suggest you read tutorial:
SRA OSS, Inc. Japan
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