swamirishi commented on code in PR #4006:
URL: https://github.com/apache/ozone/pull/4006#discussion_r1040191062


##########
hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/SCMCommonPlacementPolicy.java:
##########
@@ -426,4 +451,67 @@ public boolean isValidNode(DatanodeDetails datanodeDetails,
     }
     return false;
   }
+
+  /**
+   * Given a set of replicas of a container which are
+   * neither over underreplicated nor overreplicated,
+   * return a set of replicas to copy to another node to fix misreplication.
+   * @param replicas
+   */
+  @Override
+  public Set<ContainerReplica> replicasToCopyToFixMisreplication(
+         Set<ContainerReplica> replicas) {
+    Map<Node, List<ContainerReplica>> placementGroupReplicaIdMap
+            = replicas.stream().collect(Collectors.groupingBy(replica ->
+            this.getPlacementGroup(replica.getDatanodeDetails())));
+
+    int totalNumberOfReplicas = replicas.size();
+    int requiredNumberOfPlacementGroups =
+            getRequiredRackCount(totalNumberOfReplicas);
+    int additionalNumberOfRacksRequired = Math.max(
+            requiredNumberOfPlacementGroups - 
placementGroupReplicaIdMap.size(),
+            0);
+    int replicasPerPlacementGroup =
+            getMaxReplicasPerRack(totalNumberOfReplicas);
+    Set<ContainerReplica> copyReplicaSet = Sets.newHashSet();
+
+    for (List<ContainerReplica> replicaList: placementGroupReplicaIdMap
+            .values()) {
+      if (replicaList.size() > replicasPerPlacementGroup) {
+        List<ContainerReplica> replicasToBeCopied = replicaList.stream()
+                .limit(replicaList.size() - replicasPerPlacementGroup)
+                .collect(Collectors.toList());
+        copyReplicaSet.addAll(replicasToBeCopied);
+        replicaList.removeAll(replicasToBeCopied);
+      }
+    }
+    if (additionalNumberOfRacksRequired > copyReplicaSet.size()) {

Review Comment:
   The algorithm you are suggesting would also work.



-- 
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]

Reply via email to