YARN-7152. [ATSv2] Registering timeline client before AMRMClient service init throw exception (Rohith Sharma K S via Varun Saxena)

(cherry picked from commit ef87d34a0e96f6b6390b7086c4ea2d5b7a4c2754)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/AMRMClient.java

@@ -28,7 +28,6 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.service.AbstractService;
 import org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse;
@@ -42,7 +41,6 @@ import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.api.records.UpdateContainerRequest;
 import org.apache.hadoop.yarn.client.api.impl.AMRMClientImpl;
-import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 
 import com.google.common.base.Preconditions;
@@ -57,7 +55,6 @@ public abstract class AMRMClient<T extends AMRMClient.ContainerRequest> extends
   private static final Log LOG = LogFactory.getLog(AMRMClient.class);
 
   private TimelineV2Client timelineV2Client;
-  private boolean timelineServiceV2Enabled;
 
   /**
    * Create a new instance of AMRMClient.
@@ -82,12 +79,6 @@ public abstract class AMRMClient<T extends AMRMClient.ContainerRequest> extends
     nmTokenCache = NMTokenCache.getSingleton();
   }
 
-  @Override
-  protected void serviceInit(Configuration conf) throws Exception {
-    super.serviceInit(conf);
-    timelineServiceV2Enabled = YarnConfiguration.timelineServiceV2Enabled(conf);
-  }
-
   /**
    * Object to represent a single container request for resources. Scheduler
    * documentation should be consulted for the specifics of how the parameters
@@ -696,18 +687,9 @@ public abstract class AMRMClient<T extends AMRMClient.ContainerRequest> extends
    * V2 client will be updated dynamically if registered.
    *
    * @param client the timeline v2 client to register
-   * @throws YarnException when this method is invoked even when ATS V2 is not
-   *           configured.
    */
-  public void registerTimelineV2Client(TimelineV2Client client)
-      throws YarnException {
-    if (timelineServiceV2Enabled) {
-      timelineV2Client = client;
-    } else {
-      LOG.error("Trying to register timeline v2 client when not configured.");
-      throw new YarnException(
-          "register timeline v2 client when not configured.");
-    }
+  public void registerTimelineV2Client(TimelineV2Client client) {
+    timelineV2Client = client;
   }
 
   /**