On Mon, Jun 12, 2017 at 9:01 PM, Vladimir Borodin <r...@simply.name> wrote: > > 12 июня 2017 г., в 13:19, Amit Kapila <amit.kapil...@gmail.com> написал(а): > > On Sun, Jun 11, 2017 at 11:59 PM, Vladimir Borodin <r...@simply.name> wrote: > > > 8 июня 2017 г., в 17:03, Amit Kapila <amit.kapil...@gmail.com> написал(а): > > On Thu, Jun 8, 2017 at 6:49 PM, Dmitriy Sarafannikov > <dsarafanni...@yandex.ru> wrote: > > > Why didn't rsync made the copies on master and replica same? > > > Because rsync was running with —size-only flag. > > > IIUC the situation, the new WAL and updated pg_control file has been > copied, but not updated data files due to which the WAL has not been > replayed on replicas? If so, why the pg_control file is copied, it's > size shouldn't have changed? > > > Because on master pg_upgrade moves $prefix/9.5/data/global/pg_control to > $prefix/9.5/data/global/pg_control.old and creates new > $prefix/9.6/data/global/pg_control without making hardlink. When running > rsync from master to replica rsync sees $prefix/9.6/data/global/pg_control > on master and checks if it is a hardlink. Since it is not a hardlink and > $prefix/9.6/data/global/pg_control does not exist on replica rsync copies > it. For data files the logic is different since they are hardlinks, > corresponding files exist on replica and they are the same size. > > > Okay, in that case, I guess it is better to run Analyze on master > after the upgrade is complete (including an upgrade for replicas). If > you are worried about the performance of read-only replicas till the > time Analyze on the master in completed, you might want to use > --analyze-in-stages of vaccumdb and or use (-j njobs) along with it to > parallelize the operation. > > > What about the following sequence? > > 1. Run pg_upgrade on master, > 2. Start it in single-user mode and stop (to get right wal_level in > pg_control), > 3. Copy pg_control somewhere, >
So the above step-3 is to allow extra WAL to be replayed on replicas after the upgrade? > 4. Start master, run analyze and stop. > 5. Put the control file from step 3 to replicas and rsync them according to > the documentation. > I think the above way should work for your use case unless someone makes mistake while copying pg_control. I am sure you are ensuring to have a backup during above procedure. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
