[Bucardo-general] bucardo 5 master-master sequence odd/even?

Jonathan Brinkman jb at blackskytech.com
Mon Aug 25 13:05:14 UTC 2014


When we changed to Bucardo 5.1.1 we thought master-master syncs would handle
the primary key conflict issue without the need to manually modify the
sequences to use even/odd.
Now that we have returned to using that technique, I don't expect further
conflicts. 
But I thought the B5 upgrade meant that multi-master scenarios were handled
internally. What if I have a sync that includes (say) 5 masters? Would I
need to alter the sequences accordingly to avoid this primary-key conflict
problem (INCREMENT=5)? 
Also I had considered using a sequence strategy where each master's sequence
started with a different number (1-9 say), but that doesn't work if Bucardo
is checking/modifying the sequences for MAX on each restart. And would of
course be limited to 9 masters.

-----Original Message-----
From: Greg Sabino Mullane [mailto:greg at endpoint.com] 
Sent: Saturday, August 23, 2014 2:25 PM
To: Jonathan Brinkman
Cc: bucardo-general at bucardo.org
Subject: Re: [Bucardo-general] bucardo 5 master-master sequence odd/even?

On Thu, Aug 21, 2014 at 11:34:28AM -0400, Jonathan Brinkman wrote:
> Greetings
> When using bucardo4 with swap syncs we were instructed to set each 
> side of the swap to use dissimilar primary key ranges so that the swap 
> would never create a conflict. Like Master-A uses even keys and 
> Master-B uses odd keys (Increment 2).
> Do we still need to do that with bucardo5 in a Master-Master sync?

Yes, that is still a best pracice.

> We are seeing primary key conflicts when Master-B creates a new record 
> and apparently isn't having its sequence updated properly when 
> Master-A previously created a record (and used that primary key already).

I'm not following here - are A and B not creating odd and even primary keys?
Are the sequences based on the primary keys that Bucardo is using?

--
Greg Sabino Mullane greg at endpoint.com
End Point Corporation
PGP Key: 0x14964AC8



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