Hi Seppo, Thanks, that was my assumption as well but life tends to a little more complex than theory.
Cheers, Robert On 1/30/10 1:10 AM PST, "seppo.jaak...@codership.com" <seppo.jaak...@codership.com> wrote: > Hi Robert, > >>> Tungsten consistency checking technology works very well, and there >>> is no need to "fix it" in any way. However, this method is not directly >>> usable for multi master replication, because the target node(s) may >>> have committed some transactions not yet seen in the originating >>> master node, and these new transactions can interfere with the >>> consistency check query. >>> >> I'm sure I should really know this already, but does your statement amount >> to saying the consistency check needs to execute in total order with other >> change sets? Or are there other data visibility issues along the lines of >> non-repeatable reads that would cause you to get different answers on >> different servers? >> > > Consistency checking needs to be run in same read view in all the nodes. > (this works only for MVCC engines). > We can use total order monitor to control the start of the checking > transactions, the actual check query can then be relaxed from total order. > Which is actually crucial for this to work efficiently, as total order > operations are very expensive. > > Seppo > > -- > http://www.codership.com seppo.jaak...@codership.com > > > _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
