RE: replication followup

Two comments about sync replication:

1. You cannot do true sync replication without two-phase commit
   protocol. (What if transaction will be committed on slave but
   master will be stopped/crashed/whatever? Databases will be out
   of sync).
2. You cannot do bi-directional sync replication without distributed
   lock manager. (You'll get deadlock when attempting update "same"
   record - ie with the same key - on two sites at the same time).

Vadim
P.S. Are you sure that -general is right list for this stuff?

>     As a followup to my mail about replication yesterday, I've
> realized that I can make replication bi-directional, with each
> (non-replicant master initiated) connection to a backend it's own
> master with respect to that connection and all data
> modifications made
> within it. In order to do that, though, I need to add items to the
> structs Port (be) and PGconn (fe). After I do that, the asynch stuff
> would just fall into place, and the performance should impove. My
> question is whether there is anything I should be really careful of
> when modifying these structs? I'm not sure if there is code that uses
> byte offsets or something into these structs, so any warnings
> would be
> much appreciated.
>
> On a related note, does anyone know what the status of ER's
> replication is?
>
> -justinb
>
> --
> Justin Banks - WAM!NET Inc., Eagan MN justinb@wamnet.com
> When you find two people who agree completely, you can be pretty
> sure that exactly one of them is doing the thinking.
>
>