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https://issues.apache.org/jira/browse/FLINK-7866?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16497910#comment-16497910
]
ASF GitHub Bot commented on FLINK-7866:
---------------------------------------
Github user StefanRRichter commented on a diff in the pull request:
https://github.com/apache/flink/pull/4949#discussion_r192376303
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/clusterframework/types/SlotProfile.java
---
@@ -203,68 +206,104 @@ public
LocalityAwareRequirementsToSlotMatcher(@Nonnull Collection<TaskManagerLoc
}
// we build up two indexes, one for resource id and one
for host names of the preferred locations.
- HashSet<ResourceID> preferredResourceIDs = new
HashSet<>(locationPreferences.size());
- HashSet<String> preferredFQHostNames = new
HashSet<>(locationPreferences.size());
+ Map<ResourceID, Integer> preferredResourceIDs = new
HashMap<>(locationPreferences.size());
+ Map<String, Integer> preferredFQHostNames = new
HashMap<>(locationPreferences.size());
for (TaskManagerLocation locationPreference :
locationPreferences) {
-
preferredResourceIDs.add(locationPreference.getResourceID());
-
preferredFQHostNames.add(locationPreference.getFQDNHostname());
+ Integer oldVal =
preferredResourceIDs.getOrDefault(locationPreference.getResourceID(), 0);
+
preferredResourceIDs.put(locationPreference.getResourceID(), oldVal + 1);
+
+ oldVal =
preferredFQHostNames.getOrDefault(locationPreference.getFQDNHostname(), 0);
+
preferredFQHostNames.put(locationPreference.getFQDNHostname(), oldVal + 1);
}
Iterator<IN> iterator = candidates.iterator();
- IN matchByHostName = null;
IN matchByAdditionalRequirements = null;
+ final Map<IN, CandidateMatchedResult>
candidateMatchedResults = new HashMap<>();
+
while (iterator.hasNext()) {
IN candidate = iterator.next();
SlotContext slotContext =
contextExtractor.apply(candidate);
// this if checks if the candidate has is a
local slot
- if
(preferredResourceIDs.contains(slotContext.getTaskManagerLocation().getResourceID()))
{
+ Integer localWeigh =
preferredResourceIDs.get(slotContext.getTaskManagerLocation().getResourceID());
+ if (localWeigh != null) {
if
(additionalRequirementsFilter.test(candidate)) {
- // we can stop, because we
found a match with best possible locality.
- return
resultProducer.apply(candidate, Locality.LOCAL);
+ // we found a match with
locality.
+
candidateMatchedResults.put(candidate, new CandidateMatchedResult(localWeigh,
0));
} else {
// next candidate because this
failed on the additional requirements.
continue;
}
- }
-
- // this if checks if the candidate is at least
host-local, if we did not find another host-local
- // candidate before.
- if (matchByHostName == null) {
- if
(preferredFQHostNames.contains(slotContext.getTaskManagerLocation().getFQDNHostname()))
{
+ } else {
+ // this if checks if the candidate is
host-local.
+ Integer hostLocalWeigh =
preferredFQHostNames.get(slotContext.getTaskManagerLocation().getFQDNHostname());
+ if (hostLocalWeigh != null) {
if
(additionalRequirementsFilter.test(candidate)) {
- // We remember the
candidate, but still continue because there might still be a candidate
- // that is local to the
desired task manager.
- matchByHostName =
candidate;
+ // we found a match
with host locality.
+
candidateMatchedResults.put(candidate, new CandidateMatchedResult(0,
hostLocalWeigh));
} else {
// next candidate
because this failed on the additional requirements.
continue;
}
}
+ }
- // this if checks if the candidate at
least fulfils the resource requirements, and is only required
- // if we did not yet find a valid
candidate with better locality.
- if (matchByAdditionalRequirements ==
null
- &&
additionalRequirementsFilter.test(candidate)) {
- // Again, we remember but
continue in hope for a candidate with better locality.
- matchByAdditionalRequirements =
candidate;
- }
+ // this if checks if the candidate at least
fulfils the resource requirements, and is only required
+ // if we did not yet find a valid candidate
with better locality.
+ if (candidateMatchedResults.isEmpty()
+ && matchByAdditionalRequirements == null
+ &&
additionalRequirementsFilter.test(candidate)) {
+ // Again, we remember but continue in
hope for a candidate with better locality.
+ matchByAdditionalRequirements =
candidate;
}
}
+ // find the best matched one.
+ Map.Entry<IN, CandidateMatchedResult> theBestOne =
candidateMatchedResults.entrySet()
+ .stream()
+
.sorted(Comparator.comparingInt((Map.Entry<IN, CandidateMatchedResult>
matchResult)
+ ->
matchResult.getValue().getScore()).reversed())
+ .findFirst()
+ .orElse(null);
+
// at the end of the iteration, we return the candidate
with best possible locality or null.
- if (matchByHostName != null) {
- return resultProducer.apply(matchByHostName,
Locality.HOST_LOCAL);
+ if (theBestOne != null) {
+ return
resultProducer.apply(theBestOne.getKey(), theBestOne.getValue().getLocality());
} else if (matchByAdditionalRequirements != null) {
return
resultProducer.apply(matchByAdditionalRequirements, Locality.NON_LOCAL);
} else {
return null;
}
}
+
+ /**
+ * Helper class to record the match result.
+ */
+ private class CandidateMatchedResult {
+
+ private int localCount;
+
+ private int hostLocalCount;
+
+ public CandidateMatchedResult(int localCount, int
hostLocalCount) {
+ this.localCount = localCount;
+ this.hostLocalCount = hostLocalCount;
+ }
+
+ // evaluate the match score
+ public int getScore() {
+ return localCount * 10 + hostLocalCount * 1;
+ }
+
+ // get the highest locality.
+ public Locality getLocality() {
+ return localCount > 0 ? Locality.LOCAL :
Locality.HOST_LOCAL;
--- End diff --
What if also `hostLocal == 0`? We do still return `Locality.HOST_LOCAL`?
> Weigh list of preferred locations for scheduling
> ------------------------------------------------
>
> Key: FLINK-7866
> URL: https://issues.apache.org/jira/browse/FLINK-7866
> Project: Flink
> Issue Type: Improvement
> Components: Scheduler
> Affects Versions: 1.4.0, 1.3.2
> Reporter: Till Rohrmann
> Assignee: Sihua Zhou
> Priority: Major
> Fix For: 1.6.0
>
>
> [~sihuazhou] proposed to not only use the list of preferred locations to
> decide where to schedule a task, but to also weigh the list according to how
> often a location appeared and then select the location based on the weight.
> That way, we would obtain better locality in some cases.
> Example:
> Preferred locations list: {{[location1, location2, location2]}}
> Weighted preferred locations list {{[(location2 , 2), (location1, 1)]}}
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