Zoltan Chovan has posted comments on this change. ( http://gerrit.cloudera.org:8080/24246 )
Change subject: KUDU-3767 Add global leader awareness to auto leader rebalancer ...................................................................... Patch Set 4: > Patch Set 4: > > Regarding this scenario: > "In RunLeaderRebalanceForTable, the algorithm first computes overloaded > source tservers using only the current table’s leader distribution. If a > tserver is not overloaded for that table, it never becomes a source, even if > it is globally overloaded across many tables. > > e.g. many 1-tablet, RF=3 tables: > table1: leader on ts0 > table2: leader on ts0 > table3: leader on ts0 > > For each individual table, there is only one leader and three replicas. The > per-table target is ceil(1 / 3) = 1, so ts0 has 1 leader and is not > considered overloaded for that table. No leader_transfer_source entry is > created, so the later global tie-breaker never runs. Globally, though, ts0 > may have all leaders." > > It is true that this scenario is not addressed by this patch. This change is > Part 1 of a two-part feature described in > https://issues.apache.org/jira/browse/KUDU-3767. Part 2, which is a post-loop > global pass, is the planned follow-up that will specifically handle that > case, where every individual table is balanced at its per-table ceiling but > one tserver consistently wins that ceiling across all tables. > > Part 1 is a building block for that. In the 1-tablet RF=3 case described, the > per-table target is always ceil(1/3) = 1, so no tserver is ever considered > overloaded per-table, and the tie-breaker is never reached. Thanks for the explanation, please add some details about this in the commit msg/description -- To view, visit http://gerrit.cloudera.org:8080/24246 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I47e266d2a06d5c18a50270e0d5e9d4954480f308 Gerrit-Change-Number: 24246 Gerrit-PatchSet: 4 Gerrit-Owner: Gabriella Lotz <[email protected]> Gerrit-Reviewer: Gabriella Lotz <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Zoltan Chovan <[email protected]> Gerrit-Reviewer: Zoltan Martonka <[email protected]> Gerrit-Comment-Date: Mon, 01 Jun 2026 11:22:43 +0000 Gerrit-HasComments: No
