YARN-3986. getTransferredContainers in AbstractYarnScheduler should be present in YarnScheduler interface

(cherry picked from commit 22de7c1dca1be63d523de833163ae51bfe638a79)

hadoop-yarn-project/CHANGES.txt

@@ -734,6 +734,9 @@ Release 2.8.0 - UNRELEASED
     YARN-4028. AppBlock page key update and diagnostics value null on recovery
     (Bibin A Chundatt via xgong)
 
+    YARN-3986. getTransferredContainers in AbstractYarnScheduler should be present
+    in YarnScheduler interface instead. (Varun Saxena via rohithsharmaks)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ApplicationMasterService.java

@@ -89,7 +89,6 @@ import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAt
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAttemptStatusupdateEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.event.RMAppAttemptUnregistrationEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
-import org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.Allocation;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerNodeReport;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.YarnScheduler;
@@ -305,7 +304,7 @@ public class ApplicationMasterService extends AbstractService implements
       // and corresponding NM tokens.
       if (app.getApplicationSubmissionContext()
           .getKeepContainersAcrossApplicationAttempts()) {
-        List<Container> transferredContainers = ((AbstractYarnScheduler) rScheduler)
+        List<Container> transferredContainers = rScheduler
             .getTransferredContainers(applicationAttemptId);
         if (!transferredContainers.isEmpty()) {
           response.setContainersFromPreviousAttempts(transferredContainers);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/YarnScheduler.java

@@ -32,6 +32,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ApplicationResourceUsageReport;
+import org.apache.hadoop.yarn.api.records.Container;
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.Priority;
@@ -317,4 +318,14 @@ public interface YarnScheduler extends EventHandler<SchedulerEvent> {
    */
   public void updateApplicationPriority(Priority newPriority,
       ApplicationId applicationId) throws YarnException;
+
+  /**
+   *
+   * Get previous attempts' live containers for work-preserving AM restart.
+   *
+   * @param appAttemptId the id of the application attempt
+   *
+   * @return list of live containers for the given attempt
+   */
+  List<Container> getTransferredContainers(ApplicationAttemptId appAttemptId);
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestWorkPreservingRMRestart.java

@@ -770,7 +770,7 @@ public class TestWorkPreservingRMRestart extends ParameterizedSchedulerTestBase
       am0.getApplicationAttemptId()));
 
     // getTransferredContainers should not throw NPE.
-    ((AbstractYarnScheduler) rm2.getResourceScheduler())
+    rm2.getResourceScheduler()
       .getTransferredContainers(am0.getApplicationAttemptId());
 
     List<NMContainerStatus> containers = createNMContainerStatusForApp(am0);