kfaraz commented on code in PR #19737:
URL: https://github.com/apache/druid/pull/19737#discussion_r3646522852
##########
indexing-service/src/main/java/org/apache/druid/indexing/common/task/KillUnusedSegmentsTask.java:
##########
@@ -251,62 +258,46 @@ public TaskStatus runTask(TaskToolbox toolbox) throws
Exception
);
}
- // Kill segments. Order is important here:
- // Retrieve the segment upgrade infos for the batch _before_ the
segments are nuked
- // We then want the nuke action to clean up the metadata records
_before_ the segments are removed from storage.
- // This helps maintain that we will always have a storage segment if the
metadata segment is present.
- // Determine the subset of segments to be killed from deep storage based
on loadspecs.
- // If the segment nuke throws an exception, then the segment cleanup is
abandoned.
-
- // Determine upgraded segment ids before nuking
- final Set<String> segmentIds = unusedSegments.stream()
- .map(DataSegment::getId)
- .map(SegmentId::toString)
-
.collect(Collectors.toSet());
- final Map<String, String> upgradedFromSegmentIds = new HashMap<>();
- try {
- upgradedFromSegmentIds.putAll(
- taskActionClient.submit(
- new RetrieveUpgradedFromSegmentIdsAction(getDataSource(),
segmentIds)
- ).getUpgradedFromSegmentIds()
- );
- }
- catch (Exception e) {
- LOG.warn(
- e,
- "Could not retrieve parent segment ids using task
action[retrieveUpgradedFromSegmentIds]."
- + " Overlord may be on an older version."
- );
- }
+ // Kill segments - order of steps 1, 2, 3, 4 must remain the same
- // Nuke Segments
- taskActionClient.submit(new SegmentNukeAction(new
HashSet<>(unusedSegments)));
- emitMetric(toolbox.getEmitter(),
TaskMetrics.SEGMENTS_DELETED_FROM_METADATA_STORE, unusedSegments.size());
+ // 1. Determine parent segment ids of killable unused segments
+ final Map<String, String> upgradedFromSegmentIds
+ = fetchParentIdsForSegments(toolbox, unusedSegmentsPlus);
- // Determine segments to be killed
- final List<DataSegment> segmentsToBeKilled
- = getKillableSegments(unusedSegments, upgradedFromSegmentIds,
usedSegmentLoadSpecs, taskActionClient);
+ // 2. Identify killable segments whose load specs are not shared with
any other segment
+ final List<DataSegment> segmentsToKillFromDeepStore =
getKillableSegments(
+ unusedSegments,
+ upgradedFromSegmentIds,
+ usedSegmentLoadSpecs,
+ taskActionClient
+ );
+ // 2a. Track segments that cannot be removed from deep store yet
final Set<DataSegment> segmentsNotKilled = new HashSet<>(unusedSegments);
- segmentsToBeKilled.forEach(segmentsNotKilled::remove);
-
+ segmentsToKillFromDeepStore.forEach(segmentsNotKilled::remove);
if (!segmentsNotKilled.isEmpty()) {
LOG.warn(
- "Skipping kill of [%d] segments from deep storage as their load
specs are used by other segments.",
- segmentsNotKilled.size()
+ "Skipping kill of [%d] segments of datasource[%s] from deep
storage"
+ + " as their load specs are shared by other segments.",
+ segmentsNotKilled.size(), getDataSource()
);
}
- toolbox.getDataSegmentKiller().kill(segmentsToBeKilled);
- emitMetric(toolbox.getEmitter(),
TaskMetrics.SEGMENTS_DELETED_FROM_DEEPSTORE, segmentsToBeKilled.size());
+ // 3. Nuke all eligible unused segments
Review Comment:
It is very unlikely for this to happen. It had been called out here as well.
https://github.com/apache/druid/pull/16362#discussion_r1594909953
Essentially, the kill buffer period protects us against this.
Concurrent APPEND would only perform upgrades on a "used" segment.
And kill task would only nuke segments that have been been "unused" for a
while (default is 30 days).
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
