You mean the pgpool parent process? It won't restart by failover or any pcp command. BTW pgpool main process source code is main.c. -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp
> "After failback_command finishes, pgpool-II restart all child processes." . > How about the pgpool server process (pgpool -d -D)? Does it also get affected > when I execute pcp_recovery_node? I would like to see this source code.. > Which > files should I look into? > > > Thanks. > > > > > ________________________________ > From: Tatsuo Ishii <[email protected]> > To: [email protected] > Cc: [email protected] > Sent: Sun, May 1, 2011 3:20:31 PM > Subject: Re: [Pgpool-general] failback setup problem > >>>> >> I'm not sure what you are trying to do here. If "backup" means it was >>>> >> created by pg_dump_all, I don't think your approach works. Streaming >>>> >> replication requires a base backup(binary backup) which is managed by >>>> >> pg_start_backup/pg_stop_backup. >>>> >> >>>> > >>>> > Yes of course I have a backup created as described in >>>> > >>>>http://www.postgresql.org/docs/9.0/static/continuous-archiving.html#BACKUP-BASE-BACKUP >>>>P >> >> If you keep wal archives along with the base backup, then it should be >> possible to recover primary PostgreSQL from them of course. Question >> is, how to recover standbys. In my understanding you need to recreate >> them from the recovered primary anyway and it will require *new* base >> backup. >> >>>> > My question is, what happens if both server failed somehow? Can I still >>>> use >>>> > pgpoolAdmin to recover a database server? >>>> >>>> No, pgpoolAdmin cannot recover a database server in this situation. >>>> You have to recover the database manualy. >>>> >>> Yes. I thought that of course. >>> So my question was, if you leave the whole restore process up to one called >>> recovery script - including optional checkpointing etc. pgpool would be more >>> flexible and simplier in terms of supporting different recovery procedures. >> >> Good question. I will inspect current code if your idea is possible >> while updating docs. > > Here are steps executed in recovery procedure (described in the updted > doc today). Note that CHECK POINT is not performed in the procedure. > If all PostgreSQL servers down case, you want to skip #1 and #2 and > want to execute #3, #4, #5 by ssh. What do you think? > > 1. Pgpool-II connects to primary server's template1 database as > user = recovery_user, password = recovery_password. > > 2. Primary server executes pgpool_recovery function. > > 3. pgpool_recovery function executes > recovery_1st_stage_command. Note that PostgreSQL executes functions > with database cluster as the current directory. Thus > recovery_1st_stage_command is executed in the database cluster > directory. > > 4. Primary server executes pgpool_remote_start function. This > function executes a script named "pgpool_remote_start" in the > database cluster directory, and it executes pg_ctl command on the > standby server to be recovered via ssh. pg_ctl will start > postmaster in background. So we need to make sure that postmaster > on the standby actually starts. > > 5. pgpool-II tries to connect to the standby PostgreSQL as user = > recovery_user and password = recovery_password. The database to be > connected is "postgres" if possible. Otherwise "template1" is > used. pgpool-II retries for recovery_timeout seconds. If success, > go to next step. > > 6. If failback_command is not empty, pgpool-II parent process > executes the script. > > 7. After failback_command finishes, pgpool-II restart all child > processes. > >>> By he way - where does pgpool actually store the information about >>> attached/detached servers? >> >> On shared memory. >> -- >> Tatsuo Ishii >> SRA OSS, Inc. Japan >> English: http://www.sraoss.co.jp/index_en.php >> Japanese: http://www.sraoss.co.jp >> _______________________________________________ >> Pgpool-general mailing list >> [email protected] >> http://pgfoundry.org/mailman/listinfo/pgpool-general > _______________________________________________ > Pgpool-general mailing list > [email protected] > http://pgfoundry.org/mailman/listinfo/pgpool-general _______________________________________________ Pgpool-general mailing list [email protected] http://pgfoundry.org/mailman/listinfo/pgpool-general
