Yingchun Lai has posted comments on this change. ( http://gerrit.cloudera.org:8080/18454 )
Change subject: [master] KUDU-3390 support auto rebalance tablet leaders across TServers ...................................................................... Patch Set 29: (10 comments) http://gerrit.cloudera.org:8080/#/c/18454/19//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/18454/19//COMMIT_MSG@10 PS19, Line 10: which lead to load skew on some nodes. > I take some time to find an issue about leader imbalance at our internal JI Agree, I also saw many cases that the leader imbalanced and it lead to write and scan (especially when use LEADER_ONLY) performance degraded. http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.h File src/kudu/master/auto_leader_rebalancer.h: http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.h@59 PS29, Line 59: Initializes the auto-leader-rebalancer. nit: how about? Initializes the objects and starts the thread. or remove it? http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc File src/kudu/master/auto_leader_rebalancer.cc: http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@68 PS29, Line 68: DEFINE_uint32(auto_leader_rebalancing_rpc_timeout_seconds, 10, Add some tags for these new added flags, consider ‘experimental’, 'unsafe', 'runtime'. http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@114 PS29, Line 114: CHECK(replication_factor > 0); nit: DCHECK_GT(replication_factor, 0); http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@120 PS29, Line 120: tablet_id of leader -> uuid nit: tablet_id -> leader tserver uuid ? http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@121 PS29, Line 121: leader_uuid_map In Kudu's naming habit, the map offen named as 'value_by_key', for example leader_ts_uuid_by_tablet_id. http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@122 PS29, Line 122: tablet_id of follower -> vector<uuid> nit: tablet_id -> follower tserver uuids ? http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@124 PS29, Line 124: tserver uuid -> vector<all leaders' tablet id> : nit: tserver uuid -> leader replicas ? http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_leader_rebalancer.cc@126 PS29, Line 126: tserver uuid -> vector<all replicas' tablet id> nit: tserver uuid -> all replicas ? http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_rebalancer.cc File src/kudu/master/auto_rebalancer.cc: http://gerrit.cloudera.org:8080/#/c/18454/29/src/kudu/master/auto_rebalancer.cc@179 PS29, Line 179: nit: revert it -- To view, visit http://gerrit.cloudera.org:8080/18454 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ibfb60d8759a93b6a19238637c27df4f6b1cac918 Gerrit-Change-Number: 18454 Gerrit-PatchSet: 29 Gerrit-Owner: Yuqi Du <[email protected]> Gerrit-Reviewer: Abhishek Chennaka <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Andrew Wong <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Yifan Zhang <[email protected]> Gerrit-Reviewer: Yingchun Lai <[email protected]> Gerrit-Reviewer: Yuqi Du <[email protected]> Gerrit-Comment-Date: Sat, 24 Sep 2022 17:07:19 +0000 Gerrit-HasComments: Yes
