--- /dev/null
+<sect1 id="release-4-5-0">
+ <title>Release 4.5.0</title>
+ <note>
+ <title>Release Date</title>
+ <simpara>2023-XX-XX</simpara>
+ </note>
+
+ <sect2>
+ <title>Overview</title>
+ <para>
+ This release resolves several long-standing issues,
+ including support for multiple statements and session disconnections
+ issue in some cases. Many enhancements are also added for easier
+ configuration and administration.
+ </para>
+
+ <para>
+ Major enhancements are as follows:
+ </para>
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ Allow to use multiple statements in a query string.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Allow to set <xref linkend="guc-delay-threshold-by-time"> in milliseconds.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Avoid session disconnection issue in failover/failback/backend error in some cases.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Allow to route queries to a specific backend node for a specific user connection.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Support multiple directories specification for <xref linkend="guc-pcp-socket-dir">.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Import PostgreSQL 16's SQL parser.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </sect2>
+
+ <sect2 id="migration-4-5-0">
+ <title>Migration to Version 4.5</title>
+ <itemizedlist>
+
+ <listitem>
+ <!--
+ 2023-11-09 [4bfca73]
+ -->
+ <para>
+ The following normal ERROR messages are downgraded to DEBUG messages. (Bo Peng)
+ </para>
+ <para>
+ </para>
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ These two messages are caused when the client did not send a
+ terminate message before disconnecting to pgpool.
+ For example, when the client process was forcefully terminated, this error occurs.
+ Although they are harmless, it may sometimes confuse users.
+ </para>
+ <programlisting>
+ERROR:unable to flush data to frontend
+ </programlisting>
+ <programlisting>
+ERROR: unable to read data from frontend
+DETAIL: EOF encountered with frontend
+ </programlisting>
+ </listitem>
+ <listitem>
+ <para>
+ If <xref linkend="guc-client-idle-limit"> is set to a non-zero value,
+ the connection will be disconnected if it remains idle since the last query.
+ Because the disconnection is caused by Pgpool-II settings,
+ <productname>Pgpool-II</productname> should handle it as "DEBUG" instead of "ERROR".
+ </para>
+ <programlisting>
+ERROR: unable to read data
+DETAIL: child connection forced to terminate due to client_idle_limit:30 is reached
+ </programlisting>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-04-25 [6ec851b]
+ -->
+ <para>
+ Change default behavior of pcp commands for searching password file. (Chen Ningwei)
+ </para>
+ <para>
+ Previously pcp command does not searching for .pcppass/PCPPASSFILE
+ if <option>-w/--no-password</option> option is not given,
+ which is inconsistent with psql.
+ </para>
+ <para>
+ In the release, the default behavior is changed.
+ Since this release, <option>-w/--no-password</option> option is
+ not required to read the pcp commands password from .pcppass/PCPPASSFILE.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+ </sect2>
+
+<sect2>
+ <title>Changes</title>
+ <itemizedlist>
+
+ <listitem>
+ <!--
+ 2023-10-06 [d436949]
+ -->
+ <para>
+ Add SSH timeout in escalation.sh.sample. (Bo Peng)
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-08-19 [2efc59e]
+ -->
+ <para>
+ Allow to set <xref linkend="guc-delay-threshold-by-time"> in milliseconds. (Tatsuo Ishii)
+ </para>
+ <para>
+ Previously it was allowed only in seconds. Also put some
+ refactoring.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-August/004372.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-August/004372.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-10-30 [91369ea]
+ 2023-08-01 [8d31e90]
+ 2023-07-31 [ca300f8]
+ -->
+ <para>
+ Import PostgreSQL 16 new parser. (Chen Ningwei)
+ </para>
+ <para>
+ Major changes of PostgreSQL 16 parser include:
+ </para>
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ Add new option DEFAULT to COPY FROM
+ </para>
+ <programlisting>
+COPY ... FROM stdin WITH (default 'xx');
+ </programlisting>
+ </listitem>
+
+ <listitem>
+ <para>
+ Allow the STORAGE type to be specified by CREATE TABLE
+ </para>
+ <programlisting>
+CREATE TABLE t1 (
+ c1 VARCHAR(10) STORAGE PLAIN,
+ c2 TEXT STORAGE EXTENDED
+);
+ </programlisting>
+ </listitem>
+
+ <listitem>
+ <para>
+ Add EXPLAIN option GENERIC_PLAN to display the generic plan for a parameterized query
+ </para>
+ <programlisting>
+EXPLAIN (GENERIC_PLAN) SELECT ...;
+ </programlisting>
+ </listitem>
+
+ <listitem>
+ <para>
+ Allow subqueries in the FROM clause to omit aliases
+ </para>
+ <programlisting>
+SELECT COUNT(*) FROM (SELECT ... FROM ...);
+ </programlisting>
+ </listitem>
+
+ <listitem>
+ <para>
+ Add SQL/JSON constructors
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Add VACUUM options
+ SKIP_DATABASE_STATS, ONLY_DATABASE_STATS to skip or update all frozen statistics
+ PROCESS_MAIN to only process TOAST tables
+ </para>
+ <programlisting>
+VACUUM (SKIP_DATABASE_STATS);
+VACUUM (PROCESS_MAIN FALSE) t1 ;
+ </programlisting>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-07-24 [44fa732]
+ 2023-07-23 [4658f84]
+ -->
+ <para>
+ Add new field <literal>load_balance_node</literal> to <xref linkend="sql-show-pool-pools"> and <xref linkend="pcp-proc-info">. (Tatsuo Ishii)
+ </para>
+ <para>
+ The new field is "1" if pgpool process is connected by a client and
+ the session uses the backend id as a load balance node. Users can
+ execute the commands to find out if there's any session that uses the
+ backend as the load balance node. If so, shutting down the backend may
+ cause session disconnection.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-July/004353.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-July/004353.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-07-18 [4aa657e]
+ -->
+ <para>
+ Mitigate session disconnection issue in failover/failback/backend error. (Tatsuo Ishii)
+ </para>
+ <para>
+ Previously <productname>Pgpool-II</productname> disconnected client
+ sessions in various cases. This commit tries to avoid some of cases,
+ especially when a backend goes down and the backend is not either
+ primary (or main node) nor load balance node.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-July/004352.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-July/004352.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-06-13 [36d695d]
+ -->
+ <para>
+ Allow to route queries to a specific backend node for a specific user connection. (Bo Peng)
+ </para>
+ <para>
+ This commit adds a new parameter
+ <xref linkend="guc-user-redirect-preference-list"> to
+ allow to send SELECT queries to a specific backend node for a
+ specific user connection.
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-06-06 [e7e0315]
+ -->
+ <para>
+ Support multiple directories specification for <xref linkend="guc-pcp-socket-dir">. (Chen Ningwei)
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-05-19 [66fa78e]
+ -->
+ <para>
+ Allow to load balance <literal>PREPARE/EXECUTE/DEALLOCATE</literal>. (Tatsuo Ishii)
+ </para>
+ <para>
+ Previously <literal>PREPARE/EXECUTE/DEALLOCATE</literal> are
+ not load balanced. In streaming replication/logical replication
+ mode, they were sent to always primary node.
+ In native replication/snapshot isolation mode,
+ they were always sent to all nodes.
+ </para>
+ <para>
+ Now they can be load balanced if the SQL statement prepared by PREPARE
+ command is a read only SELECT.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-May/004334.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-May/004334.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-04-15 [df69dba]
+ 2023-04-15 [84d6699]
+ -->
+ <para>
+ Add new config parameter <xref linkend="guc-log-pcp-processes">. (Tatsuo Ishii)
+ </para>
+ <para>
+ This allows to disable logging about normal PCP Process fork and exit
+ status. When pcp command is executed, pgpool logs its fork/exit event
+ even if there's no error. This could fill up the pgpool log.
+ </para>
+ <para>
+ Abnormal fork/exit event will be logged even if the parameter is
+ disabled.
+ </para>
+ <para>
+ Patch is created by Maximilien Cuony and reviewed by Tatsuo Ishii.
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-03-25 [48da871]
+ -->
+ <para>
+ Import <literal>psqlscan</literal> source code into <productname>Pgpool-II</productname> to judge multi statement query. (Tatsuo Ishii)
+ </para>
+ <para>
+ <literal>Psqlscan</literal> is a module in the PostgreSQL source tree.
+ It is essentially subset of <productname>PostgreSQL</productname>
+ SQL scanner but it is specialized for detecting
+ the end of each SQL statement. Therefore we can count the number of
+ SQL statements in a query string by using it.
+ </para>
+ <para>
+ Discussion: https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004291.html
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-02-15 [fd32f5e]
+ 2023-02-23 [7d4dde0]
+ 2023-04-09 [3bd5f35]
+ -->
+ <para>
+ Allow to use multiple statements extensively. (Tatsuo Ishii)
+ </para>
+ <para>
+ This commit tries to eliminate pgpool's long standing limitations
+ regarding multiple statements (multi-statements).
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004287.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004287.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-03-10 [31669e9]
+ 2023-02-07 [85ce852]
+ -->
+ <para>
+ Add new configuration parameter <xref linkend="guc-notice-per-node-statement">. (Tatsuo Ishii)
+ </para>
+ <para>
+ The new GUC variable allows to emit NOTICE message of queries per
+ backend basis. It's similar to <xref linkend="guc-log-per-node-statement">
+ but as the log level is NOTICE, the log is printed on client's terminal,
+ thus users can know where their queries go to without looking into pgpool
+ log files.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004276.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004276.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2022-12-15 [57751f2]
+ -->
+ <para>
+ Enhance status file reading log. (Tatsuo Ishii)
+ </para>
+ <para>
+ Previously only if <filename>pgpool_status</filename> exists and
+ the status is down, a log message was printed. However it is more
+ useful no matter what the status (up or unused) is because it also
+ represents that pgpool_status exists and it is read while pgpool
+ starting up, which is useful information.
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-05-19 [6ce39ed]
+ -->
+ <para>
+ Remove <filename>pool_config.c</filename> and <filename>scan.c</filename>
+ from git repository. (Tatsuo Ishii)
+ </para>
+ <para>
+ They are generated files and we should not keep in the git repository.
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2022-12-14 [a493ed7]
+ 2022-12-14 [85b7e62]
+ 2022-12-13 [caeb3a8]
+ -->
+ <para>
+ Remove <filename>Makefile.in</filename> etc. generated by autoconf. (Tatsuo Ishii)
+ </para>
+ <para>
+ Also update some .ignore files and add some new .gitignore files. Now
+ developers need to run autoconf/autoreconf before compiling since the
+ generated files are not provided by git anymore.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </sect2>
+
+ <sect2>
+ <title>Bug fixes</title>
+ <itemizedlist>
+ <listitem>
+ <!--
+ 2023-09-18 [b377b1d]
+ -->
+ <para>
+ Fix race condition with <productname>Pgpool-II</productname> main and pcp child process. (Tatsuo Ishii)
+ </para>
+ <para>
+ When pcp child process is forked off, pgpool main process unblock all
+ signals. This could lead to a race condition if a signal is sent to
+ the pcp process before it sets up signal handlers. Fix is, do not
+ unblock signals until the signal handlers are set up.
+ </para>
+ <para>
+ Discussion: <ulink url="https://www.pgpool.net/pipermail/pgpool-hackers/2023-September/004398.html">https://www.pgpool.net/pipermail/pgpool-hackers/2023-September/004398.html</ulink>
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ This release fixes the same bugs as other minor releases.
+ See <xref linkend="release"> for more details of those fixes.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </sect2>
+
+ <sect2>
+ <title>Regression Tests</title>
+ <itemizedlist>
+ <listitem>
+ <!--
+ 2023-09-17 [2ee5011]
+ 2023-09-13 [fb0800e]
+ -->
+ <para>
+ Attempt to fix 001.load_balance test timeout. (Tatsuo Ishii)
+ </para>
+ </listitem>
+
+ <listitem>
+ <!--
+ 2023-02-17 [c94123a]
+ 2023-02-12 [f8c3d7b]
+ -->
+ <para>
+ Enhance regression 001.load_balance. (Tatsuo Ishii)
+ </para>
+ </listitem>
+ </itemizedlist>
+ </sect2>
+
+</sect1>
projects / pgpool2.git / commitdiff