Le 07/02/2011 09:57, Wouter D'Haeseleer a ÃcritÂ:
Question 1 : is it possible to have such a replication
configuration with the streaming replication of PG9 (cascaded
replication) ?
Nope, as far as I have tested pg only has 1 master
and can have a number of slaves, so having 2 masters is not
possible.
The second host named master2 is a slave which has slaves too, not a
master on which you can write.
Question 2 : All the procedures I have seen describing a
switchover between 2 PG servers require to copy (or rsync) the
database from the new master (old slave) to the new slave (old
master).
Is it possible to do switchover between sites (between PGMaster1
and PGMaster2) whithout copying all the database from the new PG
master to the new PG slave ?
If it is not possible yet, shall it be possible in future releases
?
Nope this is not possible, pg requires to have an
updates basebackup at the slave, this is because if you loose a
lot of streamed wal files it is impossible for the slave to
catch up and have consistent data.
--
Cyril SCETBON
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