[Pgpool-general] Preview of pgpool-II 3.0

[Tatsuo Ishii]

Hi,

Pgpool development group expects to release the first beta of
pgpool-II 3.0 in this month. Here is the release note (still under
construction). Questions, comments (including grammatical errors and
typos) are welcome.

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3.0(umiyameboshi) 2010/08/xx

	  * Version 3.0

	  This version is the first version of pgpool-II 3.0 series.
	  That is, a "major version up" from 2.2 or 2.3 series.

	  The biggest news is, this version adapts to PostgreSQL 9.0's new
	  feature: Streaming Replication/Hot Standby. Streaming
	  replication can be used as a sub mode of master slave
	  mode. Master slave mode itself heavily enhanced:

	  - SELECTs in explicit transactions can be load balanced

	  - In extended protocol, PARSE/BIND/DESCRIBE messages are sent to
        the node which execute EXECUTE message. This will reduce lock
        contention.

	  - Auto start of transaction happens only when it needed.

	  - Temporary tables can be used safely.

	  - SELECT calling functions possibly write to database executes
        on master(primary)
	  
	  Also many new features are added and major refactoring has been
	  made to the internal structure of pgpoo-II. For example, in
	  replication mode, SELECTs calling functions possibly write to
	  database will not allow to load balance.

	  * New features

	  - Online recovery can be used with master/slave/streaming
        replication mode(Tatsuo)

	  - New directive "delay_threshold" is added to monitor
        replication delay in master/slave/streaming replication
        mode. If replication delay is too much, SELECTs are not load
        balanced(Tatsuo)

	  - show pool_status shows replication delay in
        master/slave/streaming replication mode(Tatsuo)

	  - New directive "log_standby_delay" is added to control logging of
        replication delay in master/slave/streaming replication
        mode(Tatsuo)

	  - Backend process id and whether frontend connects to this
        connection pool or not are added to pcp_proc_info's
        output(Tatsuo)

      - New directive "white_function_list" and "black_function_list"
        are added to register functions those do not or do write to
        database(Tatsuo)

      - In master/slave mode, SELECTs to temporary table executes only
        on master/primary(Tatsuo)

	  - In master/slave mode, write queries outside of explicit
        transactions no longer trigger to start internal
        transaction(Tatsuo)

	  - In master/slave mode, SELECTs inside explicit transactions are
        load balanced(Tatsuo, Kitagawa)

	  - In master/slave mode, commands are not sent to all DB
        nodes. This will prevent unnecessary locking(Tatsuo, Kitagawa)

	  - New command option adds to ignore the status file when
        starting up(Tatsuo)

	  - Supports PostgreSQL 9.0's new VACUUM syntax(Tatsuo)

	  - New directive "failover_if_affected_tuples_mismatch" controls
        the behavior when number of result rows of
        INSERT/UPDATE/DELETE are differ(Tatsuo)

	  - When number of result rows of INSERT/UPDATE/DELETE are
        differ, each number are logged(Tatsuo)

	  - md5 authentication is supported in replication mode and
        master/slave mode(Tatsuo)

	  - Allow to force to move to online recovery second stage even
        there are connecting frontends(Tatsuo)

	  - If there's only one DB node and it triggers failover,
        pgpool-II will automatically connects if the DB node coming
        up(Tatsuo)

	  - Pcp commands supports long options(Guillaume Lelarge)

	  - New directive "debug_level" added to control the debug message
        logging(Tatsuo)

	  - Allow to use various boolean representations as PostgreSQL in
        pgpool.conf(Kitagawa)

	  * Bug fixes

	  - Fix bug with timeout handling in pcp commands(Tatsuo)

	  - Fix SSL hang when large amount of data transfered(Tatsuo)

	  - Fix failover when there's only one DB node(Tatsuo)
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--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp