Master/Fastmail branches - replication going to break

[ktm at rice.edu]

On Fri, Sep 19, 2014 at 03:06:59PM +1000, Bron Gondwana wrote:
> Hi Everyone,
> 
> As part of the 2.5 design, I'm nuking everything non-backwards-compatible from the replication code in the master and fastmail branches.  It's all bad and wrong.  The replication system WILL be totally backwards compatible with 2.4.
> 
> My goal is to use named vendor annotations for any feature not supported by either end, and have the upgrade code read the annotations and apply them, meaning that you can replicate from 2.5 to 2.4, and when you upgrade the replica, it should fix itself.  I haven't tested this yet, but I'm pretty sure it will be possible.
> 
> This breaks FastMail production of course, but I can babysit that one into working state again.  This is just fair warning for anyone ELSE who is running unreleased code ;)
> 
> Bron.
> 
> -- 
>   Bron Gondwana
>   brong at fastmail.fm
> 
Hi Bron,

Please, please, please allow us to replicate from 2.3 -> 2.5. We have not
been able to upgrade to 2.4 because of the impact to production services
as all mailboxes are forced to upgrade to a 2.4-style mailbox at once. The
I/O system will take a very long time to finish and the system is basically
unusable until the process is complete. If we can upgrade the replica, we can
stage the mailbox upgrades over a week or more then failover to the new 2.5
replica and repeat the process on the remaining 2.3 replicas.

Regards,
Ken