Tatsuo,

I also have some online-recory scripts that I have been meaning to  
post on the list that perhaps some could use it as another  example  
together with the ones you currently provide


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

On Dec 13, 2008, at 6:58 AM, Tatsuo Ishii wrote:

> [snip]
>
>> I can prepare ./contrib/ branch of heartbeat configuration  
>> resources to the
>> 2.2 relese if you are interested in.
>
> Great. I'd like to include your contributions into 2.2 release. I
> will create ./contrib/heartbeat directory and will put files you
> provide under it. Please provide a tar ball along with README.
>
> I'm almost ready for 2.2. F.Y.I. here is the NEWS file of 2.2.
> ----------------------------------------------------------------------
> 2.2 (urukiboshi) 2008/12/?
>         * Version 2.2
>
>         This version enhances on line recovery and fixes important bugs
>         in handling serializable transactions which could cause data
>         inconsistency among DB nodes.
>
>         * New features
>
>               - Add client_idle_limit_in_recovery directive. This will
>                 prevent 2nd stage of on line recovery from not going forward
>                 by idle clients sitting forever(Tatsuo)
>
>               - Allow to load balance DECLARE, FETCH and CLOSE(Tatsuo)
>
>         * Bug fixes
>
>               - Close all file descriptors when running in daemon mode.
>                 Otherwise we inherit sockets from apache when it's started by
>                 pgpoolAdmin. This results in that port 80 is occupied for
>                 example.  Patch provided by Akio Ishida. Also add
>                 chdir("/"). This is always good for daemon programs(Tatsuo)
>
>           - Allow MD5 authentication in raw mode as stated in
>          docs(Tatsuo)
>
>               - Check transaction serialization failure error in
>                 serializable mode and abort all nodes if so. Otherwise we
>                 allow data inconsistency among DB nodes(Tatsuo).
>
>                 See following scenario: (M:master, S:slave)
>
>                       M:S1:BEGIN;
>                       M:S2:BEGIN;
>                       S:S1:BEGIN;
>                       S:S2:BEGIN;
>                       M:S1:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       M:S2:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       S:S1:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       S:S2:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       M:S1:UPDATE t1 SET i = i + 1;
>                       S:S1:UPDATE t1 SET i = i + 1;
>                       M:S2:UPDATE t1 SET i = i + 1; <-- blocked
>                       S:S1:COMMIT;
>                       M:S1:COMMIT;
>                       M:S2:ERROR:  could not serialize access due to 
> concurrent update
>                       S:S2:UPDATE t1 SET i = i + 1; <-- success in UPDATE and 
> data  
> becomes inconsistent!
>
>               - avoid kind mismatch error caused by "SET TRANSACTION
>                 ISOLATION LEVEL must be called before any query"(Tatsuo).
>
>                  This could happen in following scenario:
>
>                   M:S1:BEGIN;
>            S:S1:BEGIN;
>                       M:S1:SELECT 1; <-- only sent to MASTER
>                       M:S1:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       S:S1:SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
>                       M: <-- error
>                       S: <-- ok since no previous SELECT is sent. kind 
> mismatch error  
> occurs!
>
>         * Incompatible changes
>
>               - Always fail over and restart all children. Before we do
>                 restart only if master has not been changed. This is
>                 wrong. If we have trouble with network cable or something,
>                 TCP/IP stack keeps on retrying for long time and the only
>                 way to prevent it is restarting process(Tatsuo)
> ----------------------------------------------------------------------
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> _______________________________________________
> Pgpool-general mailing list
> [email protected]
> http://pgfoundry.org/mailman/listinfo/pgpool-general

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