On 30 April 2011 11:42, Tatsuo Ishii <[email protected]> wrote: > >> > I have a different approach of recovering the postgres server. I'm > >> > recovering from an existing backup. I do that because it is faster and > I > >> > don't put additional i/o load on the just activated server. I guess > (or > >> > hope) most people will have an existing backup. > >> > > >> > So my question is - if the aproach of recovering the failed server via > a > >> sql > >> > command is optimal? What if both servers failed? then I'm not able to > use > >> > pcp-tools or pgpoolAdmin for recovering? > >> > >> 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 > > . > > > > 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.
By he way - where does pgpool actually store the information about attached/detached servers? Best Regards, Uwe > -- > Tatsuo Ishii > SRA OSS, Inc. Japan > English: http://www.sraoss.co.jp/index_en.php > Japanese: http://www.sraoss.co.jp > > > Best.. > > Uwe > > > > > > > >> > >> > I'm asking because I worked for several years as an > >> > it-production-responsible and I learned a little how administrators > >> > think/work. They are happy if they have a (or better ONE) defined > >> recovery > >> > procedure. > >> > Where am I getting? I'm asking you if it would makes sense to recode > or > >> > reduce the recovery procedure code to one system call e.g. > >> failback_command. > >> > Most people have their backup and restore functionality coded and > ready > >> for > >> > training and/or desaster. If they could simply use this very same > >> > functionality within pgpooladmin that would be great. > >> > > >> > It might be that i have overseen something (as before) and this is > >> already > >> > possible. If so please tell me how. > >> > > >> > Best Regards, > >> > Uwe > >> > > >> > > >> > On 26 April 2011 07:34, Tatsuo Ishii <[email protected]> wrote: > >> > > >> >> > thanks, that message already helped. I tried to recover the > postgres > >> >> server > >> >> > with the failback_command. > >> >> > >> >> You are welcome. > >> >> > >> >> > I didn't realize these recovery_* parameters yet. > >> >> > So I use the recovery_* parameters for recovering the failed > postgres > >> >> > server. > >> >> > >> >> pgpool-II connects to backend to issue some SQLs including > CHECKPOINT. > >> >> recovery_* parameters define the user and password for the > connection. > >> >> Usually they are for PostgreSQL super user (postgres). > >> >> > >> >> > And the failback_command to attach the postgres server into pgpool > >> >> > right? > >> >> > >> >> If you want to do something special, for example mailing to DBA, then > >> >> you might want to specify it. Otherwise you can leave it empty. > >> >> -- > >> >> Tatsuo Ishii > >> >> SRA OSS, Inc. Japan > >> >> English: http://www.sraoss.co.jp/index_en.php > >> >> Japanese: http://www.sraoss.co.jp > >> >> > >> >> > Best Regards, > >> >> > Uwe > >> >> > > >> >> > > >> >> > On 26 April 2011 01:06, Tatsuo Ishii <[email protected]> wrote: > >> >> > > >> >> >> > I'm using pg-pool-II 3.0.3 with streaming replication. > >> >> >> > I coded the failback scenario/script for the slave server and > the > >> >> script > >> >> >> > itself works fine. > >> >> >> > > >> >> >> > I now configured the failback script in pgpool.conf and during > >> testing > >> >> an > >> >> >> > error message comes up: > >> >> >> > 2011-04-09 06:42:18 LOG: pid 16863: starting recovering node 1 > >> >> >> > 2011-04-09 06:42:18 ERROR: pid 16863: start_recover: could not > >> connect > >> >> >> > master node. > >> >> >> > > >> >> >> > [root@adt-web01 pgpool-II-3.0.3]# pcp_node_info 10 adt-web01 > 9898 > >> >> >> postgres > >> >> >> > postgres 0 > >> >> >> > adt-db01 5432 1 0.500000 > >> >> >> > [root@adt-web01 pgpool-II-3.0.3]# pcp_node_info 10 adt-web01 > 9898 > >> >> >> postgres > >> >> >> > postgres 1 > >> >> >> > adt-db02 5432 3 0.500000 > >> >> >> > > >> >> >> > pcp commands and pgpooladmin report that the master is up and > >> running > >> >> and > >> >> >> > I'm able to connect to the master directly and through pgpool. > >> >> >> > So what's wrong? So far everything else works fine. > >> >> >> > >> >> >> Assuming you have set recovery_user and recovery_passwd correctly, > >> I'm > >> >> >> not sure what's going on. IMO, the error message is very rare. > It's > >> so > >> >> >> rare and there's a bug in the error path, which had not been found > >> for > >> >> >> long time. Can please try attached patch? The patch add a little > bit > >> >> >> usefull info to the error message above. > >> >> >> -- > >> >> >> 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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