[pgpool-general: 3837] Re: PGPool-II 3.4.2-1 not saving db state on node detach
Tatsuo Ishii
ishii at postgresql.org
Mon Jun 29 10:05:26 JST 2015
Yes, we always recommend to install rpms downloaded from the official
site (pgpool.net).
Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp
> Thanks Tatsuo,
> It does look to be an issue with the init script (I grabbed the one
> supplied from yum.postgresql.org (postgres 9.2, pgpool 3.4.2)) - I found a
> mention of the bug
> http://www.sraoss.jp/pipermail/pgpool-hackers/2012-May/000069.html
> Basically the script is running killproc and I suspect system_will_go_down
> isn't getting called.
>
> I'll cut over to the one supplied in http://git.postgresql.org/ which looks
> to be better (uses pgpool stop).
>
> This is also fixing a socket file unlinking issue I flagged here:
> http://www.sraoss.jp/pipermail/pgpool-general/2015-June/003881.html
>
>
> Cheers,
> James Elsdon
>
> On Sat, Jun 27, 2015 at 1:54 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
>
>> I have tested with 3.4.2 and could not reproduce your problem.
>> (I do not use rpm init file but do use pgpool_setup which comes with
>> pgpool source tree for testing purpose).
>>
>> t-ishii at localhost: cat log/pgpool_status <--- check initial
>> pgpool_status. Both node up.
>> up
>> up
>> t-ishii at localhost: sh startall
>> waiting for server to start....24428 2015-06-27 12:49:00 JST LOG:
>> redirecting log output to logging collector process
>> 24428 2015-06-27 12:49:00 JST HINT: Future log output will appear in
>> directory "pg_log".
>> done
>> server started
>> waiting for server to start....24442 2015-06-27 12:49:01 JST LOG:
>> redirecting log output to logging collector process
>> 24442 2015-06-27 12:49:01 JST HINT: Future log output will appear in
>> directory "pg_log".
>> done
>> server started
>> t-ishii at localhost: pcp_detach_node 0 localhost 11001 t-ishii t-ishii 1 <
>> --- let node 1 down.
>> t-ishii at localhost: psql -p 11000 -c "show pool_nodes" test <-- confirm it.
>> node_id | hostname | port | status | lb_weight | role
>> ---------+-----------+-------+--------+-----------+---------
>> 0 | /tmp | 11002 | 2 | 0.500000 | primary
>> 1 | localhost | 11003 | 3 | 0.500000 | standby
>> (2 rows)
>>
>> t-ishii at localhost: sh shutdownall <-- shudown pgpool and PostgreSQL.
>> 2015-06-27 12:49:21: pid 25079: LOG: stop request sent to pgpool. waiting
>> for termination...
>> .done.
>> waiting for server to shut down.... done
>> server stopped
>> waiting for server to shut down.... done
>> server stopped
>> t-ishii at localhost: cat log/pgpool_status <--- check pgpool_status
>> up
>> down
>> t-ishii at localhost: sh startall <-- restart pgpool and PostgreSQL
>> waiting for server to start....25093 2015-06-27 12:49:32 JST LOG:
>> redirecting log output to logging collector process
>> 25093 2015-06-27 12:49:32 JST HINT: Future log output will appear in
>> directory "pg_log".
>> done
>> server started
>> waiting for server to start....25107 2015-06-27 12:49:33 JST LOG:
>> redirecting log output to logging collector process
>> 25107 2015-06-27 12:49:33 JST HINT: Future log output will appear in
>> directory "pg_log".
>> done
>> server started
>> t-ishii at localhost: psql -p 11000 -c "show pool_nodes" test <-- check
>> pgpool status
>> node_id | hostname | port | status | lb_weight | role
>> ---------+-----------+-------+--------+-----------+---------
>> 0 | /tmp | 11002 | 2 | 0.500000 | primary
>> 1 | localhost | 11003 | 3 | 0.500000 | standby
>> (2 rows)
>>
>> > Thanks Tatsuo,
>> > What I am seeing is that the status file is *not* updated after a
>> > pcp_detatch_node so after a restart, the node is considered up again.
>> >
>> > When pgpool detects the node is down by itself however, it is written to
>> > file as expected.
>> >
>> > Regards,
>> > James Elsdon
>> >
>> > On Thursday, 25 June 2015, Tatsuo Ishii <ishii at postgresql.org> wrote:
>> >
>> >> > Hi there,
>> >> >
>> >> > I'm not sure if it's the intended behavior, but I'm seeing on
>> PGPool-II
>> >> > 3.4.2-1 that if I use pcp_detach_node - it works successfully but is
>> not
>> >> > persistent across pgpool restarts.
>> >> >
>> >> > When the node dies naturally (pgpool detaches it), the status file
>> works
>> >> > correctly - this is only on a manual pcp_detach_node
>> >> >
>> >> > [me at host ~]$ /usr/pgsql-9.2/bin/psql -U psgsuser -h psghost -p
>> pgport -c
>> >> > 'show pool_nodes'
>> >> > node_id | hostname | port | status | lb_weight | role
>> >> > ---------+----------------+------+--------+-----------+--------
>> >> > 0 | host1 | 5432 | 2 | 0.500000 | master
>> >> > 1 | host2 | 5432 | 2 | 0.500000 | slave
>> >> > (2 rows)
>> >> >
>> >> > [me at host ~]$ /usr/pgpool-9.2/bin/pcp_detach_node 10 localhost 9898
>> >> pcpuser
>> >> > pcppass 1
>> >> >
>> >> > [me at host ~]$ /usr/pgsql-9.2/bin/psql -U psgsuser -h psghost -p
>> pgport -c
>> >> > 'show pool_nodes'
>> >> > node_id | hostname | port | status | lb_weight | role
>> >> > ---------+----------------+------+--------+-----------+--------
>> >> > 0 | host1 | 5432 | 2 | 0.500000 | master
>> >> > 1 | host2 | 5432 | 3 | 0.500000 | slave
>> >> > (2 rows)
>> >> >
>> >> > [me at host ~]$ sudo cat /var/log/pgpool/pgpool_status
>> >> > up
>> >> > up
>> >> >
>> >> > [me at host ~]$ sudo /etc/init.d/pgpool-II-92 stop
>> >> > Stopping pgpool-II-92 service: [ OK ]
>> >> >
>> >> > [me at host ~]$ sudo cat /var/log/pgpool/pgpool_status
>> >> > up
>> >> > up
>> >> >
>> >> > [me at host ~]$ sudo /etc/init.d/pgpool-II-92 start
>> >> > Starting pgpool-II-92 service: [ OK ]
>> >> >
>> >> > [me at host ~]$ /usr/pgsql-9.2/bin/psql -U psgsuser -h psghost -p
>> pgport -c
>> >> > 'show pool_nodes'
>> >> > node_id | hostname | port | status | lb_weight | role
>> >> > ---------+----------------+------+--------+-----------+--------
>> >> > 0 | host1 | 5432 | 2 | 0.500000 | master
>> >> > 1 | host2 | 5432 | 2 | 0.500000 | slave
>> >> > (2 rows)
>> >> >
>> >> > [me at host ~]$ sudo cat /var/log/pgpool/pgpool_status
>> >> > up
>> >> > up
>> >> >
>> >> >
>> >> > Is this the intended behavior of pcp_detach_node ?
>> >>
>> >> Yes. pgpool-II will not change the contents of the status file until
>> >> it is told a failover event (it could be triggered by either
>> >> pcp_detach_node or failover caused by PostgreSQL backend down).
>> >>
>> >> If you do not like it, you can discard the status file and rebuild the
>> >> file by using current status, which is maintained by health checking.
>> >> (hint: pgpool -D)
>> >>
>> >> Best regards,
>> >> --
>> >> Tatsuo Ishii
>> >> SRA OSS, Inc. Japan
>> >> English: http://www.sraoss.co.jp/index_en.php
>> >> Japanese:http://www.sraoss.co.jp
>> >>
>>
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