Andrew Wong has uploaded this change for review. ( http://gerrit.cloudera.org:8080/11427
Change subject: KUDU-2463 pt 2: adjust MVCC on Raft no-op ...................................................................... KUDU-2463 pt 2: adjust MVCC on Raft no-op Based on the same rationale as Part 1 of this patch series, this patch updates MVCC's safe and clean time using the no-op timestamp provided by the leader following a successful Raft election. There isn't an obvious reference to the tablet (to get to the MVCC module) in Raft consensus, but there is a ReplicaTransactionFactory, that the TabletReplica implements. I've extended this to be a more general ConsensusRoundHandler that can be used to create transactions or finish transactions as needed. An interesting thing to note is that in some cases (e.g. brand new tablets), the first election would replicate the no-op with a timestamp of 1 (the timestamp we're trying to avoid). I tracked the cause of this to be the fact that sometimes the hybrid clock doesn't get updated before sending out the first no-op, and this will result in the first assigned timestamp being 1. To work around this, I updated the clock to the initial clean time, which seems in line with other updates to the hybrid clock in the time manager. I tested this in the following ways: - to ensure nothing terrible happens when there is a lot of election churn (and hence, a lot of timestamp advancement), I've tweaked exactly_once_writes-itest to actually churn elections. Previously it attempted this with just a low timeout; I injected some latency to make it churn a bit harder. - I added a test that ensured that, on its own, a tablet would bump its MVCC timestamps, by virtue of its elections - I tested the above with single-replica tablets as well - a few other tests needed to be tweaked given the extra bump to the hybrid clock Change-Id: Icbf812e2cbeeee7c322fd980245cfe40c886a15a --- M src/kudu/consensus/consensus-test-util.h M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/consensus/time_manager.cc M src/kudu/integration-tests/alter_table-test.cc M src/kudu/integration-tests/exactly_once_writes-itest.cc M src/kudu/integration-tests/raft_consensus-itest.cc M src/kudu/integration-tests/timestamp_advancement-itest.cc M src/kudu/tablet/tablet_replica.cc M src/kudu/tablet/tablet_replica.h 10 files changed, 179 insertions(+), 78 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/27/11427/1 -- To view, visit http://gerrit.cloudera.org:8080/11427 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: Icbf812e2cbeeee7c322fd980245cfe40c886a15a Gerrit-Change-Number: 11427 Gerrit-PatchSet: 1 Gerrit-Owner: Andrew Wong <aw...@cloudera.com>
