Anybody? On Jul 27, 2012, at 10:00 AM, Ben Chobot wrote:
> We make heavy use of streaming replication on PG 9.1 and it's been great for > us. We do have one issue with it, though, and that's when we switch master > nodes - currently, the documentation says that you must run pg_basebackup on > your old master to turn it into a slave. That makes sense when the old master > had crashed, but it seems that in the case of a planned switch, we could do > better. Here's what we tried that seemed to work... are we shooting ourselves > in the foot? > > 1. Cleanly shut down the current master. > 2. Pick a slave, turn it into the new master. > 3. Copy the new pg_xlog history file over to the old master. > 4. On any other slaves (many of our clusters are 3 nodes), we already have > "recovery_target_timeline=latest" and wal archiving, so they should already > be working as slaves of the new master. > 5. Set up recovery.conf on the old master to be like the other slaves. > 6. Start up the old master. > > Have we just avoided running pg_basebackup, or have we just given ourselves > data corruption? Because we're using wal archiving, can we simplify and leave > out step 3?
