Re: Attempting to do a rolling move to 9.2Beta (as a slave) fails

On 5/27/2012 11:08 PM, Jan Nielsen wrote:

Hi Karl,

On Sun, May 27, 2012 at 9:18 PM, Karl Denninger <karl@denninger.net> wrote:

Here's what I'm trying to do in testing 9.2Beta1.

The current configuration is a master and a hot standby at a diverse location for both hot swap and "online" backup.  Both are archived regularly so if something goes south I can recover (to either as a master.)

Okay

 

1. Build 9.2Beta1; all fine.

2. Run a pg_basebackup from the current master machine (running 9.1) to a new directory on the slave machine, using the 9.2Beta1 pg_basebackup executable.

3. Run a pg_upgrade against that from the new binary directory, producing a 9.2Beta1 data store.

4. Attempt to start the result as a SLAVE against the existing 9.1 master.

Hmm - that's likely a problem: "In general, log shipping between servers running different major PostgreSQL release levels is not possible." [1]

 

Is this caused by the version mismatch?

Probably.

Then the error message is wrong :-)

 

Do I need to run a complete parallel environment instead of trying to attach a 9.2Beta1 slave to an existing 9.1 master?  (and if so, why doesn't the code complain about the mismatch instead of the bogus WAL message?)

Slony [2] or PGBouncer+Londiste [3] should allow you to do this in an integrated fashion. [4]

I ran Slony for quite a while before 9.x showed up; I could put it back into use for a while but I really like the integrated setup that exists now with 9.x.

I'll look at doing a parallel setup but it will more limited in what I can actually validate against in terms of workload than the above was workable...