Song Jiacheng has uploaded this change for review. ( http://gerrit.cloudera.org:8080/20310
Change subject: KUDU-3497 optimize leader rebalancer algorithm Leader rebalancer might not work well for now, especilally for the tables who have less hash buckets and replication factors. For instance, for a table, consist of 9 tablets, 3 replication factor, in a 3-tser ...................................................................... KUDU-3497 optimize leader rebalancer algorithm Leader rebalancer might not work well for now, especilally for the tables who have less hash buckets and replication factors. For instance, for a table, consist of 9 tablets, 3 replication factor, in a 3-tservers cluster. Its leaders distribution is as follow: Tablet server A : 4 Tablet server B : 4 Tablet server C : 1 According to the algorithm for now, there will not be any rebalance operation scheduled. Therefore, try to find a better algorithm to make it always find the best leader distribution. The formula is: expected leader num = (tablets sum) % (tablets server num) = 0 ? (tablets sum) / (tablets server num) : ceil((tablets sum) / (tablets server num)) A tserver whose leader num is more than the expected value needs to transfer the leaderships. So the leader skew will never be more than 1. Change-Id: I0f1fe796fd98da2d8764da793b7e254319e6348a --- M src/kudu/master/auto_leader_rebalancer.cc 1 file changed, 30 insertions(+), 6 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/10/20310/1 -- To view, visit http://gerrit.cloudera.org:8080/20310 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I0f1fe796fd98da2d8764da793b7e254319e6348a Gerrit-Change-Number: 20310 Gerrit-PatchSet: 1 Gerrit-Owner: Song Jiacheng <[email protected]>
