YARN-6872. Ensure apps could run given NodeLabels are disabled post RM switchover/restart. Contributed by Sunil G

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

@@ -43,7 +43,6 @@
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.event.EventHandler;
 import org.apache.hadoop.yarn.exceptions.InvalidResourceRequestException;
-import org.apache.hadoop.yarn.exceptions.InvalidLabelResourceRequestException;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.ipc.RPCUtil;
 import org.apache.hadoop.yarn.security.AccessRequest;
@@ -65,7 +64,6 @@
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.YarnScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CSQueue;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
-import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
 import org.apache.hadoop.yarn.server.security.ApplicationACLsManager;
 import org.apache.hadoop.yarn.server.utils.BuilderUtils;
 
@@ -349,36 +347,6 @@ protected void recoverApplication(ApplicationStateData appState,
         createAndPopulateNewRMApp(appContext, appState.getSubmitTime(),
             appState.getUser(), true, appState.getStartTime());
 
-    // If null amReq has been returned, check if it is the case that
-    // application has specified node label expression while node label
-    // has been disabled. Reject the recovery of this application if it
-    // is true and give clear message so that user can react properly.
-    if (!appContext.getUnmanagedAM() &&
-        (application.getAMResourceRequests() == null ||
-            application.getAMResourceRequests().isEmpty()) &&
-        !YarnConfiguration.areNodeLabelsEnabled(this.conf)) {
-      // check application submission context and see if am resource request
-      // or application itself contains any node label expression.
-      List<ResourceRequest> amReqsFromAppContext =
-          appContext.getAMContainerResourceRequests();
-      String labelExp =
-          (amReqsFromAppContext != null && !amReqsFromAppContext.isEmpty()) ?
-          amReqsFromAppContext.get(0).getNodeLabelExpression() : null;
-      if (labelExp == null) {
-        labelExp = appContext.getNodeLabelExpression();
-      }
-      if (labelExp != null &&
-          !labelExp.equals(RMNodeLabelsManager.NO_LABEL)) {
-        String message = "Failed to recover application " + appId
-            + ". NodeLabel is not enabled in cluster, but AM resource request "
-            + "contains a label expression.";
-        LOG.warn(message);
-        application.handle(
-            new RMAppEvent(appId, RMAppEventType.APP_REJECTED, message));
-        return;
-      }
-    }
-
     application.handle(new RMAppRecoverEvent(appId, rmState));
   }
 
@@ -398,28 +366,8 @@ private RMAppImpl createAndPopulateNewRMApp(
     }
 
     ApplicationId applicationId = submissionContext.getApplicationId();
-    List<ResourceRequest> amReqs = null;
-    try {
-      amReqs = validateAndCreateResourceRequest(submissionContext, isRecovery);
-    } catch (InvalidLabelResourceRequestException e) {
-      // This can happen if the application had been submitted and run
-      // with Node Label enabled but recover with Node Label disabled.
-      // Thus there might be node label expression in the application's
-      // resource requests. If this is the case, create RmAppImpl with
-      // null amReq and reject the application later with clear error
-      // message. So that the application can still be tracked by RM
-      // after recovery and user can see what's going on and react accordingly.
-      if (isRecovery &&
-          !YarnConfiguration.areNodeLabelsEnabled(this.conf)) {
-        if (LOG.isDebugEnabled()) {
-          LOG.debug("AMResourceRequest is not created for " + applicationId
-              + ". NodeLabel is not enabled in cluster, but AM resource "
-              + "request contains a label expression.");
-        }
-      } else {
-        throw e;
-      }
-    }
+    List<ResourceRequest> amReqs = validateAndCreateResourceRequest(
+        submissionContext, isRecovery);
 
     // Verify and get the update application priority and set back to
     // submissionContext

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

@@ -67,6 +67,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
 import org.apache.hadoop.yarn.server.resourcemanager.RMServerUtils;
 import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
+import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppEventType;
@@ -518,12 +519,20 @@ private RMContainer recoverAndCreateContainer(NMContainerStatus status,
     container.setVersion(status.getVersion());
     ApplicationAttemptId attemptId =
         container.getId().getApplicationAttemptId();
+    String labelExpression = status.getNodeLabelExpression();
+    // If NodeLabel is disabled but recovered container has label expression
+    // its better to suppress that and considered as default label.
+    if (!status.getNodeLabelExpression().isEmpty() && !YarnConfiguration
+        .areNodeLabelsEnabled(rmContext.getYarnConfiguration())) {
+      labelExpression = RMNodeLabelsManager.NO_LABEL;
+    }
+
     RMContainer rmContainer =
         new RMContainerImpl(container,
             SchedulerRequestKey.extractFrom(container), attemptId,
             node.getNodeID(), applications.get(
             attemptId.getApplicationId()).getUser(), rmContext,
-            status.getCreationTime(), status.getNodeLabelExpression());
+            status.getCreationTime(), labelExpression);
     return rmContainer;
   }
 

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

@@ -22,6 +22,8 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.commons.lang.StringUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.conf.Configuration;
@@ -55,7 +57,9 @@
 @Private
 @Unstable
 public class SchedulerUtils {
-  
+
+  private static final Log LOG = LogFactory.getLog(SchedulerUtils.class);
+
   private static final RecordFactory recordFactory = 
       RecordFactoryProvider.getRecordFactory(null);
 
@@ -200,9 +204,14 @@ public static void normalizeAndValidateRequest(ResourceRequest resReq,
       String labelExp = resReq.getNodeLabelExpression();
       if (!(RMNodeLabelsManager.NO_LABEL.equals(labelExp)
           || null == labelExp)) {
-        throw new InvalidLabelResourceRequestException(
-            "Invalid resource request, node label not enabled "
-                + "but request contains label expression");
+        String message = "NodeLabel is not enabled in cluster, but resource"
+            + " request contains a label expression.";
+        LOG.warn(message);
+        if (!isRecovery) {
+          throw new InvalidLabelResourceRequestException(
+              "Invalid resource request, node label not enabled "
+                  + "but request contains label expression");
+        }
       }
     }
     if (null == queueInfo) {

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

@@ -2551,14 +2551,14 @@ protected RMNodeLabelsManager createNodeLabelManager() {
       }
     };
 
-    // rm should successfully start with app1 loaded back in FAILED state
-    // due to node label not enabled but am resource request contains
-    // node label expression.
+    // rm should successfully start with app1 loaded back in SUCCESS state
+    // by pushing app to run default label for am container and let other
+    // containers to run normally.
+
     try {
       rm2.start();
       Assert.assertTrue("RM start successfully", true);
       Assert.assertEquals(1, rm2.getRMContext().getRMApps().size());
-      rm2.waitForState(app1.getApplicationId(), RMAppState.FAILED);
     } catch (Exception e) {
       LOG.debug("Exception on start", e);
       Assert.fail("RM should start without any issue");