Mike Percy has submitted this change and it was merged. Change subject: consensus: Improve contract for API to fetch last-logged op id ......................................................................
consensus: Improve contract for API to fetch last-logged op id It's important that we differentiate between when we have a known last-logged op and when we don't actually know what it is or whether we have ever appended something to the local WAL. This applies both to the TABLET_DATA_READY case, where this information is stored in the WAL, and the TABLET_DATA_TOMBSTONED case, where this information is stored in the superblock. Cases where we are unable to determine the last-logged OpId from the WAL when a replica is in TABLET_DATA_READY state: * Early in the tablet replica lifecycle (before Raft is started). * When a replica encounters an error during initialization. Cases where we are unable to determine the last-logged OpId from the TabletMetadata when a replica is in TABLET_DATA_TOMBSTONED state: * If the replica was tombstoned while in a failed state. Included in this patch are the following API improvements: 1. Delete Log::GetLatestEntryOpId(). Previously, this method would only return something other than MinimumOpId() if a log entry had been appended during the object's lifetime. It is abandoned in favor of RaftConsensus::GetLastOpId(RECEIVED_OPID) which delegates to PeerMessageQueue::GetLastOpIdInLog(). 2. Merge PeerMessageQueue::Init() into the PeerMessageQueue constructor. This allows us to remove one lifecycle state and allows us to guarantee that, once the queue is constructed, we can always get a valid last-logged opid from it (see #1). 3. Make TabletMetadata::tombstone_last_logged_opid() return a boost::optional<OpId>. We need to clearly differentiate between when we know the last-logged opid and when we don't. We also consider MinimumOpId() to be equal to boost::none at superblock load time, since previous versions of Kudu may have written (0,0) into the TabletMetadata 'tombstone_last_logged_opid' field. Change-Id: Ia4e4501a61cd40fdee0dc918b77675a0bc2515e7 Reviewed-on: http://gerrit.cloudera.org:8080/7717 Reviewed-by: Todd Lipcon <[email protected]> Tested-by: Kudu Jenkins --- M src/kudu/consensus/consensus-test-util.h M src/kudu/consensus/consensus_peers-test.cc M src/kudu/consensus/consensus_queue-test.cc M src/kudu/consensus/consensus_queue.cc M src/kudu/consensus/consensus_queue.h M src/kudu/consensus/log.cc M src/kudu/consensus/log.h M src/kudu/consensus/mt-log-test.cc M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/consensus/raft_consensus_quorum-test.cc M src/kudu/tablet/tablet_metadata.cc M src/kudu/tablet/tablet_metadata.h M src/kudu/tablet/tablet_replica-test.cc M src/kudu/tools/kudu-tool-test.cc M src/kudu/tserver/tablet_copy_client.cc M src/kudu/tserver/tablet_copy_source_session.cc M src/kudu/tserver/tablet_service.cc M src/kudu/tserver/ts_tablet_manager.cc 19 files changed, 244 insertions(+), 242 deletions(-) Approvals: Todd Lipcon: Looks good to me, approved Kudu Jenkins: Verified -- To view, visit http://gerrit.cloudera.org:8080/7717 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: merged Gerrit-Change-Id: Ia4e4501a61cd40fdee0dc918b77675a0bc2515e7 Gerrit-PatchSet: 5 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Mike Percy <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: David Ribeiro Alves <[email protected]> Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy <[email protected]> Gerrit-Reviewer: Tidy Bot Gerrit-Reviewer: Todd Lipcon <[email protected]>
