[Pgpool-general] pgpool Online Recovery scripts example

[Marcelo Martins]

I'm also doing some tests today and indeed , like Daniel mentioned,   
it appears that I might be better off not doing anything in the  
pgpool_recovery_pitr script
and just use the recovery command to rsync the WAL files over during  
recovery. That ,of course, having the trigger file created in the  
beginning of stage 1.
I also removed the compression flag from rsync which also helps on  
speeding things up.

I'm still trying to compare the times using both types of scripts but  
it's kind of hard since there are several types of scenarios and  
several things that could impact the results which is out of  pgpool  
control.

Marcelo
PostgreSQL DBA
Linux/Solaris System Administrator
http://www.zeroaccess.org

On Dec 16, 2008, at 2:02 AM, Tatsuo Ishii wrote:

>> These have been tested under PostgreSQL 8.3.X versions
>> I have also tested these under stable version of pgpool and also the
>> latest CVS version
>> I'm sure there are things that can be improved/changed so feel free  
>> to
>> share that.
>
> Thanks. Small issues I saw in your script so far:
>
> 1) In copy-base-backup, you touch backup_in_progress file right after
>   pg_stop_backup() executed to start actual WAL archiving. I think
>   this is too late since while doing the base backup (rsync), WAL
>   segment files might be generated if there's enough updation to the
>   database. You need to start WAL archiving *before* doing base
>   backup.
>
> 2) In pgpool_recovery_pitr, you do base backup again. I think this is
>   not neccessary if you sends WAL segment files to the recovery
>   target node generated before statge two starts and will greatly
>   reduce the duration of state two.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan