On 02/10/2015 09:47 AM, Matthew Booth wrote: > On 09/02/15 18:15, Jay Pipes wrote: >> On 02/09/2015 01:02 PM, Attila Fazekas wrote: >>> I do not see why not to use `FOR UPDATE` even with multi-writer or >>> Is the retry/swap way really solves anything here. >> <snip> >>> Am I missed something ? >> >> Yes. Galera does not replicate the (internal to InnnoDB) row-level locks >> that are needed to support SELECT FOR UPDATE statements across multiple >> cluster nodes. >> >> https://groups.google.com/forum/#!msg/codership-team/Au1jVFKQv8o/QYV_Z_t5YAEJ > > Is that the right link, Jay? I'm taking your word on the write-intent > locks not being replicated, but that link seems to say the opposite. This link is better: http://www.percona.com/blog/2014/09/11/openstack-users-shed-light-on-percona-xtradb-cluster-deadlock-issues/ Specifically the line: "The local record lock held by the started transation on pxc1 didn’t play any part in replication or certification (replication happens at commit time, there was no commit there yet)." -jay