You are welcome.
> So this is done by using pcp_recovery_node command? Yes. That command will trigger everything I explained. Also, be aware that your database needs to have the pgpool stored procedures installed in order for it to work. And for them to be installed, your database needs to have the proper pl languages installed, I don't remember which one, but got to be either plpgsql or plperlu. I think it's the former. Read the pgpool tutorial for info on all this. Daniel ________________________________ From: DM [mailto:[email protected]] Sent: Tuesday, March 17, 2009 4:57 PM To: Crespo, Daniel @ SDS Cc: [email protected] Subject: Re: [Pgpool-general] Is there a option Thanks Daniel, Great Answer. So this is done by using pcp_recovery_node command? Thanks Deepak On Tue, Mar 17, 2009 at 1:30 PM, <[email protected]> wrote: Let's say you have two backends: backend0 and backend1. Supposing backend1 has failed, recoverying it (by re-synchronizing data from backend0) is expected to have a pgpool client reconnection. From the point of view of pgpool, the clients must disconnect and reconnect in order to complete a data synchronization. However, this disconnection can be very quick. The interesting part is that data synchronization (a kind of copy of the postgresql data directory) will happen while backend0 is available por reads and writes. At the end of the data transfer (1st stage), a postgresql feature (WAL archiving) helps with the synchronization of newer data (2nd stage) that has been transferred at the 1st stage. At 2nd stage is when clients must disconnect and reconnect. Pgpool has the ability to normally accept connections during 1st stage. At 2nd stage, pgpool waits until clients disconnect or until client_idle_limit_in_recovery seconds happen. Then clients get disconnected. If clients try to connect while 2nd stage happen, pgpool will block them until it finishes. Clients won't get disconnected, just will sit waiting until connection happens. I hope this helps. Daniel ________________________________ From: Crespo, Daniel @ SDS Sent: Tuesday, March 17, 2009 4:05 PM To: 'DM'; [email protected] Subject: RE: [Pgpool-general] Is there a option Yes. Look for the following keywords: pcp_recovery_node (pgpool client program) client_idle_limit_in_recovery (parameter in pgpool.conf) pgpool_copy_backup (script) pgpool_switch_xlog (script) pgpool_remote_start (script) Daniel ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of DM Sent: Tuesday, March 17, 2009 2:57 PM To: [email protected] Subject: Re: [Pgpool-general] Is there a option Hi All, Sorry I wanted to ask the question the other way round. In Pgpool is it possible to recover / sync the 2nd DB without quiescing the first. Thanks Deepak On Tue, Mar 17, 2009 at 9:48 AM, DM <[email protected]> wrote: Hi All, In pgpool Is it possible to do quiescing of a db while (recovering)/syncing the 2nd DB? Thanks Deepak
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