[Pgpool-general] pgpool-II 2.2 and pgpoolAdmin 2.2 beta1 released

[Tatsuo Ishii]

Hi,

Pgpool Global Development Group is pleased to announce the
availability of pgpool-II 2.2 and pgpoolAdmin 2.2 beta1 release.
Please grab and test them!

Please note that now the pid file location is specified by new
directive "pid_file_name" (logdir is not used anymore). pid_file_name
is defaulted to /var/run/pgpool/pgpool.pid. Make sure that you create
/var/run/pgpool/ and give it a write permission so that pgpool can
create pgpool.pid.

Here are descriptions of this release from NEWS:

-----------------------------------------------------------------
2.2 (urukiboshi) 2009/2/?
	  * Version 2.2

	  This version enhances SERIAL data type handling and on line
	  recovery. Also an important bug, serializable transactions could
	  cause data inconsistency among DB nodes, is fixed. Also query
	  cancelation, which never worked since pgpool-II was born, is
	  finally fixed.

	  * New features

		- With insert_lock, now a table is locked only if it has
          SERIAL data type and now the default value for insert_lock
          is true(Tatsuo)

		- 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)

		- Add pid_file_name directive which specifies a path to the
		  file containing pgpool process id. "logdir" is no more used(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!

		- Query cancelation now works. It never works since pgpool-II
          was born.

	  * 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)

	  * "logdir" is no more used. Instead use "pid_file_name"(Tatsuo)

--
Tatsuo Ishii
SRA OSS, Inc. Japan