YARN-11378. [Federation] Support checkForDecommissioningNodes、refreshClusterMaxPriority API's for Federation. (#5551)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/CheckForDecommissioningNodesRequest.java

@@ -19,7 +19,9 @@
 package org.apache.hadoop.yarn.server.api.protocolrecords;
 
 import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
 import org.apache.hadoop.yarn.util.Records;
 
 @Private
@@ -32,4 +34,31 @@ public abstract class CheckForDecommissioningNodesRequest {
         .newRecord(CheckForDecommissioningNodesRequest.class);
     return request;
   }
+
+  @Private
+  @Unstable
+  public static CheckForDecommissioningNodesRequest newInstance(String subClusterId) {
+    CheckForDecommissioningNodesRequest request = Records
+        .newRecord(CheckForDecommissioningNodesRequest.class);
+    request.setSubClusterId(subClusterId);
+    return request;
+  }
+
+  /**
+   * Get the subClusterId.
+   *
+   * @return subClusterId.
+   */
+  @Public
+  @Evolving
+  public abstract String getSubClusterId();
+
+  /**
+   * Set the subClusterId.
+   *
+   * @param subClusterId subCluster Id.
+   */
+  @Public
+  @Evolving
+  public abstract void setSubClusterId(String subClusterId);
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/RefreshClusterMaxPriorityRequest.java

@@ -19,7 +19,9 @@
 package org.apache.hadoop.yarn.server.api.protocolrecords;
 
 import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
 import org.apache.hadoop.yarn.util.Records;
 
 @Private
@@ -32,4 +34,31 @@ public abstract class RefreshClusterMaxPriorityRequest {
         Records.newRecord(RefreshClusterMaxPriorityRequest.class);
     return request;
   }
+
+  @Private
+  @Unstable
+  public static RefreshClusterMaxPriorityRequest newInstance(String subClusterId) {
+    RefreshClusterMaxPriorityRequest request =
+        Records.newRecord(RefreshClusterMaxPriorityRequest.class);
+    request.setSubClusterId(subClusterId);
+    return request;
+  }
+
+  /**
+   * Get the subClusterId.
+   *
+   * @return subClusterId.
+   */
+  @Public
+  @Evolving
+  public abstract String getSubClusterId();
+
+  /**
+   * Set the subClusterId.
+   *
+   * @param subClusterId subCluster Id.
+   */
+  @Public
+  @Evolving
+  public abstract void setSubClusterId(String subClusterId);
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/proto/server/yarn_server_resourcemanager_service_protos.proto

@@ -122,12 +122,14 @@ message UpdateNodeLabelsResponseProto {
 }
 
 message CheckForDecommissioningNodesRequestProto {
+  optional string sub_cluster_id = 1;
 }
 message CheckForDecommissioningNodesResponseProto {
   repeated NodeIdProto decommissioningNodes = 1;
 }
 
 message RefreshClusterMaxPriorityRequestProto {
+  optional string sub_cluster_id = 1;
 }
 message RefreshClusterMaxPriorityResponseProto {
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/impl/pb/CheckForDecommissioningNodesRequestPBImpl.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb;
 
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.CheckForDecommissioningNodesRequestProtoOrBuilder;
 import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.CheckForDecommissioningNodesRequestProto;
 import org.apache.hadoop.yarn.server.api.protocolrecords.CheckForDecommissioningNodesRequest;
 
@@ -51,6 +52,13 @@ public class CheckForDecommissioningNodesRequestPBImpl extends
     return proto;
   }
 
+  private void maybeInitBuilder() {
+    if (viaProto || builder == null) {
+      builder = CheckForDecommissioningNodesRequestProto.newBuilder(proto);
+    }
+    viaProto = false;
+  }
+
   @Override
   public int hashCode() {
     return getProto().hashCode();
@@ -70,4 +78,20 @@ public class CheckForDecommissioningNodesRequestPBImpl extends
   public String toString() {
     return TextFormat.shortDebugString(getProto());
   }
+
+  @Override
+  public String getSubClusterId() {
+    CheckForDecommissioningNodesRequestProtoOrBuilder p = viaProto ? proto : builder;
+    return (p.hasSubClusterId()) ? p.getSubClusterId() : null;
+  }
+
+  @Override
+  public void setSubClusterId(String subClusterId) {
+    maybeInitBuilder();
+    if (subClusterId == null) {
+      builder.clearSubClusterId();
+      return;
+    }
+    builder.setSubClusterId(subClusterId);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/impl/pb/RefreshClusterMaxPriorityRequestPBImpl.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.yarn.server.api.protocolrecords.impl.pb;
 
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.RefreshClusterMaxPriorityRequestProtoOrBuilder;
 import org.apache.hadoop.yarn.proto.YarnServerResourceManagerServiceProtos.RefreshClusterMaxPriorityRequestProto;
 import org.apache.hadoop.yarn.server.api.protocolrecords.RefreshClusterMaxPriorityRequest;
 
@@ -27,9 +28,7 @@ import org.apache.hadoop.thirdparty.protobuf.TextFormat;
 
 @Private
 @Unstable
-public class RefreshClusterMaxPriorityRequestPBImpl 
- extends
-    RefreshClusterMaxPriorityRequest {
+public class RefreshClusterMaxPriorityRequestPBImpl extends RefreshClusterMaxPriorityRequest {
 
   RefreshClusterMaxPriorityRequestProto proto =
       RefreshClusterMaxPriorityRequestProto.getDefaultInstance();
@@ -52,6 +51,13 @@ public class RefreshClusterMaxPriorityRequestPBImpl
     return proto;
   }
 
+  private void maybeInitBuilder() {
+    if (viaProto || builder == null) {
+      builder = RefreshClusterMaxPriorityRequestProto.newBuilder(proto);
+    }
+    viaProto = false;
+  }
+  
   @Override
   public int hashCode() {
     return getProto().hashCode();
@@ -71,4 +77,20 @@ public class RefreshClusterMaxPriorityRequestPBImpl
   public String toString() {
     return TextFormat.shortDebugString(getProto());
   }
+
+  @Override
+  public String getSubClusterId() {
+    RefreshClusterMaxPriorityRequestProtoOrBuilder p = viaProto ? proto : builder;
+    return (p.hasSubClusterId()) ? p.getSubClusterId() : null;
+  }
+
+  @Override
+  public void setSubClusterId(String subClusterId) {
+    maybeInitBuilder();
+    if (subClusterId == null) {
+      builder.clearSubClusterId();
+      return;
+    }
+    builder.setSubClusterId(subClusterId);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/RouterMetrics.java

@@ -171,6 +171,10 @@ public final class RouterMetrics {
   private MutableGaugeInt numUpdateNodeResourceFailedRetrieved;
   @Metric("# of refreshNodesResources failed to be retrieved")
   private MutableGaugeInt numRefreshNodesResourcesFailedRetrieved;
+  @Metric("# of checkForDecommissioningNodes failed to be retrieved")
+  private MutableGaugeInt numCheckForDecommissioningNodesFailedRetrieved;
+  @Metric("# of refreshClusterMaxPriority failed to be retrieved")
+  private MutableGaugeInt numRefreshClusterMaxPriorityFailedRetrieved;
 
   // Aggregate metrics are shared, and don't have to be looked up per call
   @Metric("Total number of successful Submitted apps and latency(ms)")
@@ -303,6 +307,10 @@ public final class RouterMetrics {
   private MutableRate totalSucceededUpdateNodeResourceRetrieved;
   @Metric("Total number of successful Retrieved RefreshNodesResources and latency(ms)")
   private MutableRate totalSucceededRefreshNodesResourcesRetrieved;
+  @Metric("Total number of successful Retrieved CheckForDecommissioningNodes and latency(ms)")
+  private MutableRate totalSucceededCheckForDecommissioningNodesRetrieved;
+  @Metric("Total number of successful Retrieved RefreshClusterMaxPriority and latency(ms)")
+  private MutableRate totalSucceededRefreshClusterMaxPriorityRetrieved;
 
   /**
    * Provide quantile counters for all latencies.
@@ -372,6 +380,8 @@ public final class RouterMetrics {
   private MutableQuantiles getClusterUserInfoLatency;
   private MutableQuantiles updateNodeResourceLatency;
   private MutableQuantiles refreshNodesResourcesLatency;
+  private MutableQuantiles checkForDecommissioningNodesLatency;
+  private MutableQuantiles refreshClusterMaxPriorityLatency;
 
   private static volatile RouterMetrics instance = null;
   private static MetricsRegistry registry;
@@ -599,6 +609,13 @@ public final class RouterMetrics {
 
     refreshNodesResourcesLatency = registry.newQuantiles("refreshNodesResourcesLatency",
         "latency of refresh nodes resources timeouts", "ops", "latency", 10);
+
+    checkForDecommissioningNodesLatency = registry.newQuantiles(
+        "checkForDecommissioningNodesLatency", "latency of check for decommissioningnodes timeouts",
+        "ops", "latency", 10);
+
+    refreshClusterMaxPriorityLatency = registry.newQuantiles("refreshClusterMaxPriorityLatency",
+        "latency of refresh cluster max priority timeouts", "ops", "latency", 10);
   }
 
   public static RouterMetrics getMetrics() {
@@ -925,6 +942,16 @@ public final class RouterMetrics {
     return totalSucceededRefreshNodesResourcesRetrieved.lastStat().numSamples();
   }
 
+  @VisibleForTesting
+  public long getNumSucceededCheckForDecommissioningNodesRetrieved() {
+    return totalSucceededCheckForDecommissioningNodesRetrieved.lastStat().numSamples();
+  }
+
+  @VisibleForTesting
+  public long getNumSucceededRefreshClusterMaxPriorityRetrieved() {
+    return totalSucceededRefreshClusterMaxPriorityRetrieved.lastStat().numSamples();
+  }
+
   @VisibleForTesting
   public long getNumSucceededRefreshSuperUserGroupsConfigurationRetrieved() {
     return totalSucceededRefreshSuperUserGroupsConfigurationRetrieved.lastStat().numSamples();
@@ -1245,6 +1272,16 @@ public final class RouterMetrics {
     return totalSucceededRefreshNodesResourcesRetrieved.lastStat().mean();
   }
 
+  @VisibleForTesting
+  public double getLatencySucceededCheckForDecommissioningNodesRetrieved() {
+    return totalSucceededCheckForDecommissioningNodesRetrieved.lastStat().mean();
+  }
+
+  @VisibleForTesting
+  public double getLatencySucceededRefreshClusterMaxPriorityRetrieved() {
+    return totalSucceededRefreshClusterMaxPriorityRetrieved.lastStat().mean();
+  }
+
   @VisibleForTesting
   public double getLatencySucceededRefreshSuperUserGroupsConfigurationRetrieved() {
     return totalSucceededRefreshSuperUserGroupsConfigurationRetrieved.lastStat().mean();
@@ -1514,6 +1551,14 @@ public final class RouterMetrics {
     return numRefreshNodesResourcesFailedRetrieved.value();
   }
 
+  public int getCheckForDecommissioningNodesFailedRetrieved() {
+    return numCheckForDecommissioningNodesFailedRetrieved.value();
+  }
+
+  public int getRefreshClusterMaxPriorityFailedRetrieved() {
+    return numRefreshClusterMaxPriorityFailedRetrieved.value();
+  }
+
   public int getDelegationTokenFailedRetrieved() {
     return numGetDelegationTokenFailedRetrieved.value();
   }
@@ -1847,6 +1892,16 @@ public final class RouterMetrics {
     refreshNodesResourcesLatency.add(duration);
   }
 
+  public void succeededCheckForDecommissioningNodesRetrieved(long duration) {
+    totalSucceededCheckForDecommissioningNodesRetrieved.add(duration);
+    checkForDecommissioningNodesLatency.add(duration);
+  }
+
+  public void succeededRefreshClusterMaxPriorityRetrieved(long duration) {
+    totalSucceededRefreshClusterMaxPriorityRetrieved.add(duration);
+    refreshClusterMaxPriorityLatency.add(duration);
+  }
+
   public void succeededRefreshSuperUserGroupsConfRetrieved(long duration) {
     totalSucceededRefreshSuperUserGroupsConfigurationRetrieved.add(duration);
     refreshSuperUserGroupsConfLatency.add(duration);
@@ -2091,6 +2146,14 @@ public final class RouterMetrics {
     numRefreshNodesResourcesFailedRetrieved.incr();
   }
 
+  public void incrCheckForDecommissioningNodesFailedRetrieved() {
+    numCheckForDecommissioningNodesFailedRetrieved.incr();
+  }
+
+  public void incrRefreshClusterMaxPriorityFailedRetrieved() {
+    numRefreshClusterMaxPriorityFailedRetrieved.incr();
+  }
+
   public void incrGetDelegationTokenFailedRetrieved() {
     numGetDelegationTokenFailedRetrieved.incr();
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/rmadmin/FederationRMAdminInterceptor.java

@@ -27,6 +27,7 @@ import org.apache.hadoop.fs.CommonConfigurationKeys;
 import org.apache.hadoop.ipc.StandbyException;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;
+import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
@@ -70,14 +71,17 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 import java.util.Collection;
+import java.util.Set;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 
 public class FederationRMAdminInterceptor extends AbstractRMAdminRequestInterceptor {
 
@@ -623,16 +627,89 @@ public class FederationRMAdminInterceptor extends AbstractRMAdminRequestIntercep
 
   @Override
   public CheckForDecommissioningNodesResponse checkForDecommissioningNodes(
-      CheckForDecommissioningNodesRequest checkForDecommissioningNodesRequest)
-      throws YarnException, IOException {
-    throw new NotImplementedException();
+      CheckForDecommissioningNodesRequest request) throws YarnException, IOException {
+
+    // Parameter check
+    if (request == null) {
+      RouterServerUtil.logAndThrowException("Missing checkForDecommissioningNodes request.", null);
+      routerMetrics.incrCheckForDecommissioningNodesFailedRetrieved();
+    }
+
+    String subClusterId = request.getSubClusterId();
+    if (StringUtils.isBlank(subClusterId)) {
+      routerMetrics.incrCheckForDecommissioningNodesFailedRetrieved();
+      RouterServerUtil.logAndThrowException("Missing checkForDecommissioningNodes SubClusterId.",
+          null);
+    }
+
+    try {
+      long startTime = clock.getTime();
+      RMAdminProtocolMethod remoteMethod = new RMAdminProtocolMethod(
+          new Class[]{CheckForDecommissioningNodesRequest.class}, new Object[]{request});
+
+      Collection<CheckForDecommissioningNodesResponse> responses =
+          remoteMethod.invokeConcurrent(this, CheckForDecommissioningNodesResponse.class,
+          subClusterId);
+
+      if (CollectionUtils.isNotEmpty(responses)) {
+        // We selected a subCluster, the list is not empty and size=1.
+        List<CheckForDecommissioningNodesResponse> collects =
+            responses.stream().collect(Collectors.toList());
+        if (!collects.isEmpty() && collects.size() == 1) {
+          CheckForDecommissioningNodesResponse response = collects.get(0);
+          long stopTime = clock.getTime();
+          routerMetrics.succeededCheckForDecommissioningNodesRetrieved((stopTime - startTime));
+          Set<NodeId> nodes = response.getDecommissioningNodes();
+          return CheckForDecommissioningNodesResponse.newInstance(nodes);
+        }
+      }
+    } catch (YarnException e) {
+      routerMetrics.incrCheckForDecommissioningNodesFailedRetrieved();
+      RouterServerUtil.logAndThrowException(e,
+          "Unable to checkForDecommissioningNodes due to exception " + e.getMessage());
+    }
+
+    routerMetrics.incrCheckForDecommissioningNodesFailedRetrieved();
+    throw new YarnException("Unable to checkForDecommissioningNodes.");
   }
 
   @Override
   public RefreshClusterMaxPriorityResponse refreshClusterMaxPriority(
-      RefreshClusterMaxPriorityRequest request)
-      throws YarnException, IOException {
-    throw new NotImplementedException();
+      RefreshClusterMaxPriorityRequest request) throws YarnException, IOException {
+
+    // parameter verification.
+    if (request == null) {
+      routerMetrics.incrRefreshClusterMaxPriorityFailedRetrieved();
+      RouterServerUtil.logAndThrowException("Missing RefreshClusterMaxPriority request.", null);
+    }
+
+    String subClusterId = request.getSubClusterId();
+    if (StringUtils.isBlank(subClusterId)) {
+      routerMetrics.incrRefreshClusterMaxPriorityFailedRetrieved();
+      RouterServerUtil.logAndThrowException("Missing RefreshClusterMaxPriority SubClusterId.",
+          null);
+    }
+
+    try {
+      long startTime = clock.getTime();
+      RMAdminProtocolMethod remoteMethod = new RMAdminProtocolMethod(
+          new Class[]{RefreshClusterMaxPriorityRequest.class}, new Object[]{request});
+      Collection<RefreshClusterMaxPriorityResponse> refreshClusterMaxPriorityResps =
+          remoteMethod.invokeConcurrent(this, RefreshClusterMaxPriorityResponse.class,
+          subClusterId);
+      if (CollectionUtils.isNotEmpty(refreshClusterMaxPriorityResps)) {
+        long stopTime = clock.getTime();
+        routerMetrics.succeededRefreshClusterMaxPriorityRetrieved(stopTime - startTime);
+        return RefreshClusterMaxPriorityResponse.newInstance();
+      }
+    } catch (YarnException e) {
+      routerMetrics.incrRefreshClusterMaxPriorityFailedRetrieved();
+      RouterServerUtil.logAndThrowException(e,
+          "Unable to refreshClusterMaxPriority due to exception. " + e.getMessage());
+    }
+
+    routerMetrics.incrRefreshClusterMaxPriorityFailedRetrieved();
+    throw new YarnException("Unable to refreshClusterMaxPriority.");
   }
 
   @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/TestRouterMetrics.java

@@ -598,6 +598,16 @@ public class TestRouterMetrics {
       LOG.info("Mocked: failed refreshNodesResources call");
       metrics.incrRefreshNodesResourcesFailedRetrieved();
     }
+
+    public void getCheckForDecommissioningNodesFailed() {
+      LOG.info("Mocked: failed checkForDecommissioningNodes call");
+      metrics.incrCheckForDecommissioningNodesFailedRetrieved();
+    }
+
+    public void getRefreshClusterMaxPriorityFailed() {
+      LOG.info("Mocked: failed refreshClusterMaxPriority call");
+      metrics.incrRefreshClusterMaxPriorityFailedRetrieved();
+    }
   }
 
   // Records successes for all calls
@@ -898,6 +908,18 @@ public class TestRouterMetrics {
       LOG.info("Mocked: successful RefreshNodesResourcesRetrieved call with duration {}", duration);
       metrics.succeededRefreshNodesResourcesRetrieved(duration);
     }
+
+    public void getCheckForDecommissioningNodesRetrieved(long duration) {
+      LOG.info("Mocked: successful CheckForDecommissioningNodesRetrieved call with duration {}",
+          duration);
+      metrics.succeededCheckForDecommissioningNodesRetrieved(duration);
+    }
+
+    public void getRefreshClusterMaxPriorityRetrieved(long duration) {
+      LOG.info("Mocked: successful RefreshClusterMaxPriority call with duration {}",
+          duration);
+      metrics.succeededRefreshClusterMaxPriorityRetrieved(duration);
+    }
   }
 
   @Test
@@ -2042,4 +2064,49 @@ public class TestRouterMetrics {
     Assert.assertEquals(225,
         metrics.getLatencySucceededRefreshNodesResourcesRetrieved(), ASSERT_DOUBLE_DELTA);
   }
+
+  @Test
+  public void testCheckForDecommissioningNodesFailedRetrieved() {
+    long totalBadBefore = metrics.getCheckForDecommissioningNodesFailedRetrieved();
+    badSubCluster.getCheckForDecommissioningNodesFailed();
+    Assert.assertEquals(totalBadBefore + 1,
+        metrics.getCheckForDecommissioningNodesFailedRetrieved());
+  }
+
+  @Test
+  public void testCheckForDecommissioningNodesRetrieved() {
+    long totalGoodBefore = metrics.getNumSucceededCheckForDecommissioningNodesRetrieved();
+    goodSubCluster.getCheckForDecommissioningNodesRetrieved(150);
+    Assert.assertEquals(totalGoodBefore + 1,
+        metrics.getNumSucceededCheckForDecommissioningNodesRetrieved());
+    Assert.assertEquals(150,
+        metrics.getLatencySucceededCheckForDecommissioningNodesRetrieved(), ASSERT_DOUBLE_DELTA);
+    goodSubCluster.getCheckForDecommissioningNodesRetrieved(300);
+    Assert.assertEquals(totalGoodBefore + 2,
+        metrics.getNumSucceededCheckForDecommissioningNodesRetrieved());
+    Assert.assertEquals(225,
+        metrics.getLatencySucceededCheckForDecommissioningNodesRetrieved(), ASSERT_DOUBLE_DELTA);
+  }
+
+  @Test
+  public void testRefreshClusterMaxPriorityFailedRetrieved() {
+    long totalBadBefore = metrics.getRefreshClusterMaxPriorityFailedRetrieved();
+    badSubCluster.getRefreshClusterMaxPriorityFailed();
+    Assert.assertEquals(totalBadBefore + 1, metrics.getRefreshClusterMaxPriorityFailedRetrieved());
+  }
+
+  @Test
+  public void testRefreshClusterMaxPriorityRetrieved() {
+    long totalGoodBefore = metrics.getNumSucceededRefreshClusterMaxPriorityRetrieved();
+    goodSubCluster.getRefreshClusterMaxPriorityRetrieved(150);
+    Assert.assertEquals(totalGoodBefore + 1,
+        metrics.getNumSucceededRefreshClusterMaxPriorityRetrieved());
+    Assert.assertEquals(150,
+        metrics.getLatencySucceededRefreshClusterMaxPriorityRetrieved(), ASSERT_DOUBLE_DELTA);
+    goodSubCluster.getRefreshClusterMaxPriorityRetrieved(300);
+    Assert.assertEquals(totalGoodBefore + 2,
+        metrics.getNumSucceededRefreshClusterMaxPriorityRetrieved());
+    Assert.assertEquals(225,
+        metrics.getLatencySucceededRefreshClusterMaxPriorityRetrieved(), ASSERT_DOUBLE_DELTA);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/rmadmin/TestFederationRMAdminInterceptor.java

@@ -49,6 +49,8 @@ import org.apache.hadoop.yarn.server.api.protocolrecords.RemoveFromClusterNodeLa
 import org.apache.hadoop.yarn.server.api.protocolrecords.RemoveFromClusterNodeLabelsResponse;
 import org.apache.hadoop.yarn.server.api.protocolrecords.ReplaceLabelsOnNodeRequest;
 import org.apache.hadoop.yarn.server.api.protocolrecords.ReplaceLabelsOnNodeResponse;
+import org.apache.hadoop.yarn.server.api.protocolrecords.CheckForDecommissioningNodesRequest;
+import org.apache.hadoop.yarn.server.api.protocolrecords.CheckForDecommissioningNodesResponse;
 import org.apache.hadoop.yarn.server.federation.store.impl.MemoryFederationStateStore;
 import org.apache.hadoop.yarn.server.federation.store.records.SubClusterId;
 import org.apache.hadoop.yarn.server.federation.utils.FederationStateStoreFacade;
@@ -65,6 +67,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.HashSet;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
 /**
@@ -521,4 +524,30 @@ public class TestFederationRMAdminInterceptor extends BaseRouterRMAdminTest {
         "subClusterId = SC-NON is not an active subCluster.",
         () -> interceptor.replaceLabelsOnNode(request2));
   }
+
+  @Test
+  public void testCheckForDecommissioningNodesRequest() throws Exception {
+    // null request1.
+    LambdaTestUtils.intercept(YarnException.class, "Missing checkForDecommissioningNodes request.",
+        () -> interceptor.checkForDecommissioningNodes(null));
+
+    // null request2.
+    CheckForDecommissioningNodesRequest request =
+        CheckForDecommissioningNodesRequest.newInstance(null);
+    LambdaTestUtils.intercept(YarnException.class,
+        "Missing checkForDecommissioningNodes SubClusterId.",
+        () -> interceptor.checkForDecommissioningNodes(request));
+  }
+
+  @Test
+  public void testCheckForDecommissioningNodesNormalRequest() throws Exception {
+    CheckForDecommissioningNodesRequest request =
+        CheckForDecommissioningNodesRequest.newInstance("SC-1");
+    CheckForDecommissioningNodesResponse response =
+        interceptor.checkForDecommissioningNodes(request);
+    assertNotNull(response);
+    Set<NodeId> nodeIds = response.getDecommissioningNodes();
+    assertNotNull(nodeIds);
+    assertEquals(0, nodeIds.size());
+  }
 }