Ashwani Raina has posted comments on this change. ( http://gerrit.cloudera.org:8080/24618 )
Change subject: KUDU-3734 Compaction budget refinements and observability ...................................................................... Patch Set 3: (7 comments) http://gerrit.cloudera.org:8080/#/c/24618/2//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/24618/2//COMMIT_MSG@7 PS2, Line 7: KUDU-3734 Compaction budget refinements and obser > nit: does this come under some umbrella JIRA ticket? If yes, maybe mention It doesn't come under an umbrella ticket as such but this can be considered as follow-up to KUDU-3734. I will add the ticket number in the heading. http://gerrit.cloudera.org:8080/#/c/24618/2//COMMIT_MSG@27 PS2, Line 27: Metrics to detect slow scans caused by budget-induced compaction lag > Are these per-tablet or total for a tablet server? Would be nice to clarif Done http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/diskrowset.cc File src/kudu/tablet/diskrowset.cc: http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/diskrowset.cc@838 PS2, Line 838: return base_data_->OnDiskColumnDataSize(col_id); : } : return 0; > Maybe, add a flag validator for rowset_undo_deltas_budget_weight to be more Done http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet.cc File src/kudu/tablet/tablet.cc: http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet.cc@2570 PS2, Line 2570: ntries added unconditionally above; underflow is imp > nit: add a DCHECK() to make sure there isn't an underflow of unsigned integ ret should always have the main MRS entry and per txn MRS entry in total, so it is impossible to underflow. Added the debug check to make it explicit. http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet.cc@2589 PS2, Line 2589: : // Record the number of DiskRowSet iterators opened for th > ditto Same as above. http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet_metrics.cc File src/kudu/tablet/tablet_metrics.cc: http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet_metrics.cc@447 PS2, Line 447: A non-zero value is expected in " : "normal operation; a persistent rising rat > Isn't it quite common to have a situation where there many other rowsets wi Yes, this is a common scenario and the reason to mention it here was to ensure that whoever reads the counter (in the even debugging a problem) doesn't consider this as a 100% problem and end up taking the wrong direction RCA. On other other hand, it might beat the purpose if user is not aware of how compaction policy works. But, I see your point about this may turning into a noise. Also, the next statement after this clearly states that a non-zero value could be a normal scenario. Removed the highlighted line. http://gerrit.cloudera.org:8080/#/c/24618/2/src/kudu/tablet/tablet_metrics.cc@462 PS2, Line 462: "Compaction Budget Health", : kudu::MetricUnit::kUnits, : "Health indicator for compaction budget adequacy. Set to 1 (degraded) " : "when one or more DiskRowSets are individually larger than " : "--tablet_compaction_budget_mb and can therefore never be selected for " : "merge compaction under the current settings. A degraded state means " : "affected rowsets will accumulate indefinitely, which may cause slow scans. " : "Set to 0 (healthy) when all candidate rowsets fit within the budget. " : "To resolve a degraded state, increase --tablet_compaction_budget_mb or, " : "if --rowset_deltas_size_include_undo is enabled, lower " : "--rowset_undo_deltas_budget_weight.", : kudu::MetricLevel::kInfo); : > From the monitoring perspective, it might be quite cumbersome to watch for Done -- To view, visit http://gerrit.cloudera.org:8080/24618 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Id63db0006c77ad1d55eb2119d99ee64499435819 Gerrit-Change-Number: 24618 Gerrit-PatchSet: 3 Gerrit-Owner: Ashwani Raina <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Ashwani Raina <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Comment-Date: Thu, 30 Jul 2026 12:37:34 +0000 Gerrit-HasComments: Yes
