NEWS

2.3 (tomiteboshi) 2009/12/07

	  * Version 2.3

	  This version enhances replication, especially CURRENT_TIMESTAMP,
	  CURRENT_DATE, now() etc. now can be properly replicated. Also
	  perforance of replication when num_init_children == 1 is
	  enhanced. Pgpool-II now records the status of down nodes, and
	  remember when it restarts to ensure that keep the node status as
	  before. Also some logs are enhanced and more fine fail over
	  controls are added. Please note that pgpool-II 2.3 includes all
	  of enhancements and fixes of pgpool-II 2.2.1 to 2.2.6.

	  * Incompatibilities from 2.2.x

	  - pgpool_status file is created under logdir. So you need to
        give write permission to the directory so that pgpool-II can
        read/write pgpool_status file.

	  * Enhancements

	  - Enable proper replication of results of temporal functions
        (CURRENT_TIMESTAMP, CURRENT_DATE, now() etc.). Now
        applications can execute INSERT/UPDATE tables which include
        defaut values using those temporal functions. There are small
        limitations. See restriction sections of docs for more
        details (Akio Ishida)

	  - Use PostgreSQL 8.4's SQL parser(Akio Ishida)

	  - Enhance the performance 20% to 100% of replication when
		num_init_children == 1(Tatsuo)

	  - Add new directive log_per_node_statement which is similar to
        log_statement except that prints info for each DB node to make
        it easier which query is sent to which DB node(Tatsuo)

	  - Add new directive fail_over_on_backend_error to control the
		 behaviro of fail over(Tatsuo)

	  - Record DB node status and remember when pgpool-II restarts(Tatsuo)

	  - EXPLAIN and EXPLAIN ANALYZE for SELECT query are now load
        balanced. This will prevent unwanted kind mismatch errors when
        EXPLAIN produces slightly different plan(Tatsuo)

	  - Enhance CSS of pgpool-ja.html(Tatsuo)

	  - Add sample configuration file for replication mode and
        master/slave mode(Tatsuo)

	 - Add test for temporal data(Akio Ishida)

2.2.6 (urukiboshi) 2009/12/01

	  * Version 2.2.6

	  This version enhances handling of backend weight. Also it allows
	  to use temp tables in master/slave mode. It includes various
	  fixes for bugs in 2.2.5 or before as usual.

	  * Bug fixes

	  - Do not allow to load balance DECLARE, CLOSE, FETCH and
        MOVE. If data gets updated and CLOSE issued after transaction
        commit(i.e. holdbale cursor), this will cause data
        inconsistency since CLOSE is executed one of the severs,
        rather than all(Tatsuo)

	  - In master/slave mode, execute Parse message on only master
        node. In previous versions Parse executed on all nodes, which
        grabbed unneccessary lock(Tatsuo)

	  - Remove init script from all runlevels before uninstall(Devrim)

	  - Fix pgpoo.spec(Devrim)

	  - Do not execute REINDEX DATABASE or SYSTEM, CREATE/DROP TABLE
        SPACE inside a transaction block(Tatsuo)

	  * Enhancements

	  - Allow to change weight by reloading pgool.conf. This will take
        effect for next client sessions(Tatsuo)

	  - Reply with usefull error messages, rather than "server closed
        the connection unexpectedly" when authentication fails(Glyn
        Astill)

	  - Add info to logs when writing to sockets falis to know if it
        was for backend or frontend(Tatsuo)

	  - Do not complain when writing to socket of frontend
        fails(Tatsuo)

	  - Allow to use temp tables in master/slave
        mode. INSERT/UPDATE/DELETE will automatically be sent to
        master only. Still SELECT you need to add /*NO LOAD BALANCE*/
        comment(Tatsuo)

	  - Add temp table test to test/jdbc(Tatsuo)

2.2.5 (urukiboshi) 2009/10/4
	  * Version 2.2.5

	  This version fixes various bugs in 2.2.4 or before.

	  * Bug fixes

	  - Fix connection_count_down(). It decrements the connection
        counter too much in some corner cases and causes online
        recover never completes(Tatsuo)

	  - Detect frontend exiting while waiting for commands complete in
        other cases such as internal locks are issued and Parse
        (Tatsuo)

	  - Fix inifinit loop in reset_backend(Xavier Noguer, Tatsuo)

	  - Fix Parse() to print actual query when it detects kind
        mismatch error(Tatsuo)

	  - Document enhancements(Tatsuo)

2.2.4 (urukiboshi) 2009/8/24
	  * Version 2.2.4

	  This version fixes various bugs in 2.2.3 or before.

	  * Bug fixes

	  - Fix possible bug introduced in pgpool-II 2.2.2.  Load balance
		control variables may remain not be restored and subsequent
		DML/DDL call might sent to only master node(Tatsuo)

	  - Send NOTICE message to frontend periodically if V2 protocol is
		used. This is ifdef out since it affectes visible change to
		applications.  2.2.3 unconditionaly sends param packet to
		client even it uses version 2 protocol, which is apparentlt
		wrong. Also tweak checking period from 1 second to 30 seconds
		since 1 second seems too aggressive(Tatsuo)

	  - Block signals before forking children rather after.  Otherwise
		parent will be killed by failover signal if it receives a
		signal before establishing signal handler(Tatsuo)

	  - Remove unnecessary spaces and tabs at the end of line(Jun Kuriyama)

2.2.3 (urukiboshi) 2009/8/11
	  * Version 2.2.3

	  This version fixes various bugs in 2.2.2 or before.

	  * Bug fixes

	  - Fix child process death if one of backends is not available(Tatsuo).

	  - Fix various parallel query bugs(Yoshiharu Mori)

	  - Fix message corruption for kid mismatch error(Akio Ishida)

	  - Now stetmemt_time works(Tatsuo)

	  - Enhance health checking to detect postmaster stopping by
        SIGSTOP(Tatsuo)

	  - Detect frontend abnormal exiting while waiting for reply from
        backend. This only works with V3 protocol(Tatsuo)

	  - Do not start internal transaction if command is CLUSTER
        without arguments(Tatsuo)

	  - Fix bug with COPY FROM in that backend process remains after
        COPY failed(Tatsuo)

	  * Enhancements

	  - Show last query for extended protocol(Akio Ishida)

	  - Allow to compile sql/pgpool-recovery/pgpool-recovery.c with
        PostgreSQL 8.4(Tatsuo)

2.2.2 (urukiboshi) 2009/5/5
	  * Version 2.2.2

	  This version fixes various bugs in 2.2.1 or before. Please note
	  that an importan fix is made to avoid data incositency risk,
	  which could happen when client does not exit gracely(without
	  sending "X" packet) while pgpool is trying to send data to
	  it. This could happen with all version of pgpool-II.

	  * Bug fixes

	  - Ignore write error on frontend connection. This is needed to
		continue processing with backend, otherwise we risk data
		incositency(Tatsuo)

	  - Fix bug introduced in 2.2.1 (In master slave mode, sometimes
	  	DEALLOCATE fails). If prepared statement reused, pgpool
	  	hangs(Toshihiro)

	  - Fix pgpool crash when SQL command PREPARE and protocol level
        EXECUTE are mixed. The bug was introduced in 2.2(Tatsuo)

	  - Avoid "unexpected EOF on client connection" error in PostgreSQL
        when reset query fails(Tatsuo)
		
2.2.1 (urukiboshi) 2009/4/25
	  * Version 2.2.1

	  This version fixes various bugs in 2.2.

	  * Bug fixes

	  - In master slave mode, sometimes DEALLOCATE fails. This is
		caused by that the first PREPARE was not executed on the
		slave(Toshihiro)

	  - Update pgpool.spec along with related files(Devrim)

	  - Fix inser_lock so that it is ignored when protocol version is
        2(Tatsuo)
		
	  - Remove excessive log messages regarding parameter change notice(Tatsuo)

	  - Add missing files to doc(Tatsuo)

2.2 (urukiboshi) 2009/2/28
	  * 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. Query
	  cancelation, which never worked since pgpool-II was born, is
	  finally fixed.

	  * New features/enhancements

		- 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)

		- Start internal transaction other than INSERT, UPDATE, DELETE
          and SELECT to keep node consistency(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)

		- Add -d option to pcp commands(Jun Kuriyama)

		- Enahnce kind mismatch error message to include originarl
          query string(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!

		- Process status display has extra space on FreeeBSD(Jun Kuriyama)

		- Fix incorrect kind mismatch detection case. e.g: BEGIN;
		  BEGIN; (Tatsuo)

	    - If PostgreSQL sends lots of DEBUG message, sometimes pgpool
	      complains:
		  2008-11-08 22:41:53 ERROR: pid 23744: do_command: backend does not
		  return ReadyForQuery. This due to a wrong assumption for the
		  client/server protocol(Tatsuo)

		- Fix the case when sending an erronous query to abort
          transaction. It assumed that after sending an error query,
          always ReadyForQuery came right after that. If some
          debugging or logging verboseness is set, PostgreSQL might
          sends NOTICE before ReadyForQuery(Tatsuo)

		- Query cancelation now works. It never worked since pgpool-II
          was born(Tatsuo)

		- Fix online recovery to wait for failback done before
          allowing to accept connections from clients. It was supposed
          to work like this but actually was not since the day 0 when
          online recovery was born. Without the fix there could be
          potential data inconsistency among DB nodes(Tatsuo)

		- Fix pgpool-II crash after on line recovery. This happens
          after the failback process adds a recovered node which has
          no connection to the node(Tatsuo)

		- Fix pgpool-II errors when postgresql.conf is reloaded. This
          was caused by parameter status packet sent asynchronously
          from backend, which indicates the internal setting of
          backend has been changed(Tatsuo)

	  * 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)

		- Default value for insert_lock is now true(Tatsuo)

2.1 (inamiboshi) 2008/7/25
      * Version 2.1

      * New feature
        - Add '%m' format to failover_command and failback_command to
          obtain new master node ID. (Yoshiyuki)
        - Add '%m' format to failover_command and failback_command to
          obtain old master node ID. (Yoshiyuki)
        - Add new directive "recovery_timeout" to specify recovery
          timeout in second. (Taiki)
        - Add optino '-v' to print pgpool version. (Yoshiyuki)

      * Incompatibility
        - Restrict pgpool_recovery() and pgpool_remote_start()
          functions to superusers. (Yoshiyuki)
        - Do not create a connection pool to standby node in raw
          mode. (Yoshiyuki)
        - Remove "replication_timeout" parameter. (Yoshiyuki)
          - This enabled if replication_strict was false. However,
            replication_strict was already removed.
        - Ignore timeout argument of pcp commands. (Taiki)
        - Do not replicate "COPY TO STDOUT" when replicate_select is
          false. (Yoshiyuki)

      * Bug fix
      ** General
        - Fix crash when CloseComplete message was
          received. (Yoshiyuki)
        - Improve network I/O routine. (Yoshiyuki)
        - Fix compile errors on Solaris 10. (Yoshiyuki)
        - Improve log messages of health check and recovery. (Tatsuo)
        - Change error level of the "failed to read kind from
          frontend" message from ERROR to LOG. (Yoshiyuki)
        - Fix failover failure in raw mode. (Taiki)
        - Fix zombie process bug. (Yoshiyuki)
        - Fix health_check_timeout to work correctly. (Kenichi Sawada)
        - Support ps status on FreeBSD. (ISHIDA Akio)
        - Improve bind(2) failure report. (Jun Kuriyama)
        - Improve error message when client authentication
          failed. (Tatsuo)

      ** Replication
        - Fix replicate_select to work correctly. (Tatsuo)
        - Fix a wrong rollback bug with extended query. (Yoshiyuki)
        - Fix a bug with asynchronous query. (Yoshiyuki)
        - Fix hint clause handling like /*REPLICATION*/ with extended
          query. (Yoshiyuki)
        - Fix crash of "DEALLOCATE ALL". (Yoshiyuki)
        - Fix hang up when a backend node does immediate
          shutdown. (Yoshiyuki)
        - Fix hang up online recovery in high load. (Yoshiyuki)
        - Fix hang up with extended query protocol when SELECT is
          failed inside a transaction block. (Yoshiyuki)

      ** Master Slave
        - Fix load balancing to work correctly. (Yoshiyuki)
        - Fix crash if SET, PREPARE or DEALLOCATE is executed inside a
          transaction block. (Yoshiyuki)

      ** Parallel query
        - Fix INSERT failure. (Yoshiharu)
        - Fix syntax error when a query contains "AS" in FROM
          clause. (sho)
        - Fix Hung up when two or more statment was executed 
          in parallel mode (Yoshiharu)
        - Fix Query rewriting of Join Expression and DISTINCT ON
          (Yoshiharu)

2.0.1 (hikitsuboshi) 2007/11/21
      * Version 2.0.1
      * Fix process down with UPDATE or DELETE query.(Yoshiyuki)
      * Send a syntax query only to a master node if master_slave is
        true.(Yoshiyuki)

2.0 (hikitsuboshi) 2007/11/16
      * Version 2.0

      * Incompatibility since pgpool-II 1.x
        - the default value for ignore_leading_white_space is now
          true(Yoshiyuki) 
        - replicate_strict is removed. The value is always
          true(Yoshiyuki)

      * General
        - Allow to reload pgpool.conf(Yoshiyuki)
        - The paraser is now compatible with PostgreSQL 8.3(Yoshiyuki)
        - Add new directive "failover_command" to specify command when
          a node is detached(Yoshiyuki)
        - Add new directive "client_idle_limit" to specify the time out since
          the last command is arrived from a client(Tatsuo)
  
      * Replication
        - Always start a new transaction even if the query is not in
          an explicit transaction to enhance the reliabilty of
          replication(Yoshiyuki)
        - Enhance the performance of replication for write
          queries. Now the worst case is 1/2 compared with single DB
          node regardless the number of DB nodes. Previous release
          tends to degrade according to the numer of DB
          nodes(Yoshiyuki)
        - Add "online recovery" which allows to add a DB node and sync
          with other DB nodes without stopping the pgpool
          server(Yoshiyuki)
        - Abort a transaction if INSERT, UPDATE and DELETE reports
          different number of result rows(Yoshiyuki)

          x=# update t set a = a + 1;
          ERROR:  pgpool detected difference of the number of update tuples
          HINT:  check data consistency between master and other db node

        - If the results from DB nodes do not match, select the
          possible correct result by "decide by majority". Previous
          release always trust the result of the master DB
          node(Yoshiyuki)
        - Allow load balance in V2 frontend/backend protocol(Yoshiyuki)

      * Parallel query
        - Allow "partial replication" to enhance the performance of
          the parallel query(Yoshiharu)

1.3 (sohiboshi) 2007/10/23
      * Version 1.3
      * Add new "authentication_timeout" directive, being the default
        value is 60. (Yoshiyuki)
        - Maximum time in seconds to complete client authentication.
      * Reject a connection when startup packet length is greater than
        10,000 byte. (Yoshiyuki)
      * Fix invalid memory access when pgpool processed DEALLOCATE
        statement. (Yoshiyuki)
      * Fix hang up in load balance mode. (Yoshiyuki)
        - This was introduced in V1.2.
      * Fix segmentation fault in 64-bit environment when query cache
        is enable. (Yoshiyuki)

1.2.1 (tomoboshi) 2007/09/28
      * Version 1.2.1
      * Fix deadlock while processing Parse message. (Yoshiyuki)
      * Fix memory leak in reset_prepared_list(). (Yoshiyuki)
      * Fix compile error on FreeBSD 4.11. (Yoshiyuki)
      * SET, PREPARE and DEALLOCATE statements are replicated in
        master/slave mode. (Yoshiyuki)

1.2 (tomoboshi) 2007/08/01
      * Version 1.2
      * Add new "replicate_select" directive, being the default value
        is false. (Yoshiyuki) 
        - If it is true, SELECT query is replicated. This behavior is
          same as V3.2 or earlier.
      * Improve signal handling. (Yoshiyuki)
        - Occasionaly, zombie processes were remained. Or processes
          were unstable.
      * Fix hang up when SELECT was error inside a transaction
        block. The bug was introduced in V3.3. (Yoshiyuki)
      * Fix PREPARE/EXECUTE handling in master slave mode. (Yoshiyuki)
      * Fix "kind mismatch error" when deadlock error 
      * Fix hang up and SEGV in extended query protocol when a warning
        SQL like "SELECT '\'';" executed. (Yoshiyuki)
      * Fix hang up when postmaster did fast or immediate
        shutdown. (Yoshiyuki)
      * Fix memory leak when connection cache was full. (Yoshiyuki)
      * Load balancing node is selected when a session
        starts. (Yoshiyuki)
      * Fix buffer overrun if connection_life_time was
        set. (Yoshiyuki)

1.1.1 (amiboshi) 2007/6/15
      * Version 1.1.1
      * Fix "kind mismatch" bug when load_balance_mode is true
        introduced in 1.1 (Yoshiyuki)
      * Fix deadlock with extended query protocol(Yoshiyuki)
      * Fix numerous bugs with protocol V2(Yoshiyuki)

1.1 (amiboshi) 2007/5/25
      * Version 1.1
      * Support HBA authentication(Taiki)
      * Support log_connections(Taiki)
      * Support log_hostname(Taiki)
      * Show pgpool status in ps command(Taiki)
      * Fix compile error on MacOS X(Yoshiyuki)
      * Allow load balancing with extended protocol(Yoshiyuki)
      * Improve replication. SELECT nextval() and SELECT setval() are
        now replicated. (Yoshiyuki)
      * Change SELECT query is only sent to the master node. (Yoshiyuki)
        - Use /*REPLICATION*/ comment to repliate a SELECT query.
      * Fix unexpected failover error due to receiving an interrupt
        signal while connecting to the backend. (Yoshiyuki)
      * Add "pgpool.pam" file, for PAM configuration file, to be
        installed under "$PREFIX/share/pgpool-II/". (Taiki)
      * Fix core dump when executing large SQL. (Yoshiyuki)

1.0.2 (suboshi) 2007/02/12
      * Version 1.0.2
      * Fix bug when executing large SQL to prevent pgpool goes into
        infinite loop(Yoshiyuki)
      * Fix bug with extended protocol handling(Yoshiyuki)
      * Enhance log for failover and failback(Tatsuo)
      * Add backend status info to show pool_status(Tatsuo)
      * Fix UPDATE/DELETE returns wrong number of rows(Tatsuo)
      * Fix configure fails to link libpq when used with older
        version of gcc(Yoshiyuki)
      * Fix DEALLOCATE treatment when used with PHP:PDO DBD-Pg(Yoshiyuki)
      * Do not load balance SELECT FOR UPDATE, SELECT INTO and SELECT
        with comments. This behavior is compatible with
        pgpool-I(Yoshiyuki)
      * Obtain path to libpq using pg_config. --with-pgsql will be
        removed in next version(Yoshiyuki) 
      * When reusing connection pool, reconnect to backend if the
        socket is broken(Yoshiyuki)
      * Fix error with configure when used with PostgreSQL
        7.4(Yoshiyuki)

1.0.1 (suboshi) 2006/09/22
      * Version 1.0.1
      * This version fixes bugs including master/slave not being
        working, deadlock problem in COPY FROM STDIN. Also documents
        are improved.

1.0.0 (suboshi) 2006/09/08
      * Initial release

Local Variables:
mode: outline
End: