>> BTW, I have a question: in my understanding, what pcp_promote_node >> will do is a) create a protomoe request in shared memory area, b) do a >> failover and restart child process. Promoting standby node to primary >> seems out of scope of this tool. >> >> We can do this by 1)stop PostgreSQL primary node, 2) then create a >> trigger file on the appropreate standby node 3) thsese steps can be >> managed by fail over scrip of pgpool-II. So it seems we can do what >> you want in current pgpool without using pcp_protomote_node. >> >> WHat's the use case for pcp_promoto_node? > Yes, it is almost possible to do a lot of thing manually or by scripting > with pgpool. This patch I think is useful because you have a command to > tell to pgpool who should be the new master and let pgpool doing the > right things internally. In this patch actually it don't do much more > than you explain above but in the future we can take fine control of > this step, like pausing client connections during the switch or anything > else.
Thanks for clarification. That sounds reasonable to me. BTW, after applying the patches I got following errors while doing online recovery. In my testing node 0 is down status and is the recovery target. Node 1 is up and running as primary node. This worked perfectly before applying your patches. Thoought? 2011-03-09 08:37:17 ERROR: pid 15531: health check failed. 0 th host /tmp at port 5433 is down 2011-03-09 08:37:17 LOG: pid 15531: set 0 th backend down status 2011-03-09 08:37:17 LOG: pid 15531: starting degeneration. shutdown host /tmp(5433) 2011-03-09 08:37:17 LOG: pid 15531: execute command: /usr/local/etc/failover.sh 0 "/tmp" 5433 /usr/local/pgsql/data 1 0 "/tmp" 0 2011-03-09 08:37:17 LOG: pid 15531: find_primary_node: 1 node is standby 2011-03-09 08:37:17 LOG: pid 15531: find_primary_node: no primary node found 2011-03-09 08:37:17 LOG: pid 15531: Primary node id saved: -1 2011-03-09 08:37:17 LOG: pid 15531: failover done. shutdown host /tmp(5433) 2011-03-09 08:37:34 LOG: pid 15566: starting recovering node 0 2011-03-09 08:37:34 ERROR: pid 15566: start_recover: could not connect master node. -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp _______________________________________________ Pgpool-hackers mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-hackers
