Re: 9.3 to 9.5 upgrade problems - Mailing list pgsql-general

On 07/03/2016 08:06 AM, Andy Colson wrote:
> Hi all,
>
> I have a master (web1) and two slaves (web2, webserv), one slave is
> quite far from the master, the db is 112 Gig, so pg_basebackup is my
> last resort.
>
> I followed the page here:
> https://www.postgresql.org/docs/9.5/static/pgupgrade.html
>
> including the rsync stuff.  I practiced it _twice_, once in PG 9.5 beta,
> and again a week ago, on two VM's I created locally.  Both practice
> sessions worked perfect.
>
> I just ran it on the live databases.  The master seems ok, its running
> PG 9.5 now, I can login to it, and no errors in the log.
>
> Neither slave works.  After I'd gotten done with the pgupgrade steps,
> both slaves gave me this error:
>
> FATAL:  database system identifier differs between the primary and standby
>
> Sure enough pg_controldata show'd their database system id different
> (all three web1, web2, webserv were different.  no matches at all), so
> I'm assuming the rsync didnt rsync right, or I missed a step and ran it
> to early, or something ... I'm not quite sure.
>
> I needed to get the live website back up and running again, so I let the
> master go, ran analyze, and when it was finished, used the steps here to
> try and resync:
>
> https://wiki.postgresql.org/wiki/Binary_Replication_Tutorial
>
> on Master:
> select pg_start_backup('clone',true);
> rsync -av --exclude pg_xlog --exclude postgresql.conf /pub/pg95/*
> web2:/pub/pg95/
> select pg_stop_backup();
> rsync -av /pub/pg95/pg_xlog web2:/pub/pg95/

Not sure about above rsync, that seems to undo what you did previously.

Also was the remote directory empty when you did this?

>
>
> That ran pretty quick, and pg_controldata shows matching numbers, but
> when I start the slave I get:
>
> ,,2016-07-03 06:06:57.173 CDT,: LOG:  entering standby mode
> ,,2016-07-03 06:06:57.205 CDT,: LOG:  redo starts at 369/D6002228
> ,,2016-07-03 06:06:57.984 CDT,: LOG:  consistent recovery state reached
> at 369/DCC5DB90
> ,,2016-07-03 06:06:57.984 CDT,: LOG:  database system is ready to accept
> read only connections
> ,,2016-07-03 06:06:57.984 CDT,: LOG:  invalid record length at 369/DD038ED0
> ,,2016-07-03 06:06:58.344 CDT,: LOG:  started streaming WAL from primary
> at 369/DD000000 on timeline 1
> web,[unknown],2016-07-03 06:07:11.176 CDT,[local]: FATAL:  role "andy"
> does not exist
>
> I can login as myself on the master, but not on the slave.  when I "psql
> -U postgres" on the slave I get:
>
> psql: FATAL:  cache lookup failed for database 16401
>
> This is only on web2, its close to web1, so I'm hoping I can get it
> fixed and then rsync it quickly to the far away slave.
>
> I'm at a loss here, any hints or suggestions would be appreciated.
>
> Thanks,
>
> -Andy
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com