Mike Percy has posted comments on this change. Change subject: design-docs: multi-master for 1.0 release ......................................................................
Patch Set 4: (2 comments) http://gerrit.cloudera.org:8080/#/c/2527/4/docs/design-docs/multi-master-1.0.md File docs/design-docs/multi-master-1.0.md: Line 275: master replicates via Raft before triggering a state change. It doesn't > To clarify, does the TS use the term that is agreed upon by the majority of I think something like this is as good as persistence, since we're piggy-backing on the master cluster's raft persistence. Line 278: allow for replicating no-ops (i.e. log entries that needn't be persisted). > Your point about the existing invariant in administrative RPCs is well take With the leasing algorithm, I think what needs to be done is wait for an election timeout after getting elected before acting. Right? And same goes if you're a leader, you can't do anything unless you've gotten replies in the last election timeout. Assuming relative time is very close to the same for each node, this provides mutual exclusion. Regarding the delete calls, yes the first one seems like it could just be a warning to me. The third one is also possibly benign because I don't think one can "undelete" a table, considering that it should be identified by the table id, not table name. So unprotected access should be safe. However, in general I am not sure basing a CAS on tablet config version protects against split-brain masters. It's primarily intended to protect against a master that has stale information relative to the tablet's raft configuration, not a master that has bad information about whether a replica is alive, for example. -- To view, visit http://gerrit.cloudera.org:8080/2527 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Iad76012977a45370b72a04d608371cecf90442ef Gerrit-PatchSet: 4 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Adar Dembo <[email protected]> Gerrit-Reviewer: Adar Dembo <[email protected]> Gerrit-Reviewer: Dan Burkert <[email protected]> Gerrit-Reviewer: David Ribeiro Alves <[email protected]> Gerrit-Reviewer: Jean-Daniel Cryans Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy <[email protected]> Gerrit-Reviewer: Todd Lipcon <[email protected]> Gerrit-HasComments: Yes
