YARN-6572. Refactoring Router services to use common util classes for pipeline creations. (#4594)

2022-08-10 05:44:29 +08:00 · 2022-08-10 05:44:29 +08:00 · ffa9ed93a4
commit ffa9ed93a4
parent 92abd99450
6 changed files with 116 additions and 227 deletions
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/utils/YarnServerBuilderUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/utils/YarnServerBuilderUtils.java
@ -79,7 +79,7 @@ public static NodeHeartbeatResponse newNodeHeartbeatResponse(int responseId,
   *
   * @param applicationId Application ID
   * @param credentials HDFS Tokens
-   * @return systemCredentialsForAppsProto SystemCredentialsForAppsProto
+   * @return systemCredentialsForAppsProto
   */
  public static SystemCredentialsForAppsProto newSystemCredentialsForAppsProto(
      ApplicationId applicationId, ByteBuffer credentials) {
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/RouterServerUtil.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/RouterServerUtil.java
@ -21,10 +21,19 @@
 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.conf.Configuration;
+import org.apache.hadoop.util.ReflectionUtils;
+import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import java.io.IOException;

 /**
@ -84,6 +93,74 @@ public static void logAndThrowException(String errMsg, Throwable t)
    }
  }

+  public static <R> R createRequestInterceptorChain(Configuration conf, String pipeLineClassName,
+      String interceptorClassName, Class<R> clazz) {
+
+    List<String> interceptorClassNames = getInterceptorClassNames(conf,
+        pipeLineClassName, interceptorClassName);
+
+    R pipeline = null;
+    R current = null;
+
+    for (String className : interceptorClassNames) {
+      try {
+        Class<?> interceptorClass = conf.getClassByName(className);
+        if (clazz.isAssignableFrom(interceptorClass)) {
+          Object interceptorInstance = ReflectionUtils.newInstance(interceptorClass, conf);
+          if (pipeline == null) {
+            pipeline = clazz.cast(interceptorInstance);
+            current = clazz.cast(interceptorInstance);
+            continue;
+          } else {
+            Method method = clazz.getMethod("setNextInterceptor", clazz);
+            method.invoke(current, interceptorInstance);
+            current = clazz.cast(interceptorInstance);
+          }
+        } else {
+          LOG.error("Class: {} not instance of {}.", className, clazz.getCanonicalName());
+          throw new YarnRuntimeException("Class: " + className + " not instance of "
+              + clazz.getCanonicalName());
+        }
+      } catch (ClassNotFoundException e) {
+        LOG.error("Could not instantiate RequestInterceptor: {}", className, e);
+        throw new YarnRuntimeException("Could not instantiate RequestInterceptor: " + className, e);
+      } catch (InvocationTargetException e) {
+        LOG.error("RequestInterceptor {} call setNextInterceptor error.", className, e);
+        throw new YarnRuntimeException("RequestInterceptor " + className
+            + " call setNextInterceptor error.", e);
+      } catch (NoSuchMethodException e) {
+        LOG.error("RequestInterceptor {} does not contain the method setNextInterceptor.",
+            className);
+        throw new YarnRuntimeException("RequestInterceptor " + className +
+            " does not contain the method setNextInterceptor.", e);
+      } catch (IllegalAccessException e) {
+        LOG.error("RequestInterceptor {} call the method setNextInterceptor " +
+            "does not have access.", className);
+        throw new YarnRuntimeException("RequestInterceptor "
+            + className + " call the method setNextInterceptor does not have access.", e);
+      }
+    }
+
+    if (pipeline == null) {
+      throw new YarnRuntimeException(
+          "RequestInterceptor pipeline is not configured in the system.");
+    }
+
+    return pipeline;
+  }
+
+  private static List<String> getInterceptorClassNames(Configuration conf,
+      String pipeLineClass, String interceptorClass) {
+    String configuredInterceptorClassNames = conf.get(pipeLineClass, interceptorClass);
+    List<String> interceptorClassNames = new ArrayList<>();
+    Collection<String> tempList =
+        StringUtils.getStringCollection(configuredInterceptorClassNames);
+    for (String item : tempList) {
+      interceptorClassNames.add(item.trim());
+    }
+    return interceptorClassNames;
+  }
+
  /**
   * Throws an IOException due to an error.
   *
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/clientrm/RouterClientRMService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/clientrm/RouterClientRMService.java
@ -20,10 +20,7 @@

 import java.io.IOException;
 import java.net.InetSocketAddress;
-import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import java.util.Map;

 import org.apache.hadoop.classification.InterfaceAudience.Private;
@ -33,8 +30,6 @@
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.PolicyProvider;
 import org.apache.hadoop.service.AbstractService;
-import org.apache.hadoop.util.ReflectionUtils;
-import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.api.ApplicationClientProtocol;
 import org.apache.hadoop.yarn.api.protocolrecords.CancelDelegationTokenRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.CancelDelegationTokenResponse;
@ -108,8 +103,8 @@
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationTimeoutsResponse;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
-import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.apache.hadoop.yarn.ipc.YarnRPC;
+import org.apache.hadoop.yarn.server.router.RouterServerUtil;
 import org.apache.hadoop.yarn.server.router.security.authorize.RouterPolicyProvider;
 import org.apache.hadoop.yarn.util.LRUCacheHashMap;
 import org.slf4j.Logger;
@ -147,7 +142,7 @@ public RouterClientRMService() {

  @Override
  protected void serviceStart() throws Exception {
-    LOG.info("Starting Router ClientRMService");
+    LOG.info("Starting Router ClientRMService.");
    Configuration conf = getConfig();
    YarnRPC rpc = YarnRPC.create(conf);
    UserGroupInformation.setConfiguration(conf);
@ -161,9 +156,7 @@ protected void serviceStart() throws Exception {
    int maxCacheSize =
        conf.getInt(YarnConfiguration.ROUTER_PIPELINE_CACHE_MAX_SIZE,
            YarnConfiguration.DEFAULT_ROUTER_PIPELINE_CACHE_MAX_SIZE);
-    this.userPipelineMap = Collections.synchronizedMap(
-        new LRUCacheHashMap<String, RequestInterceptorChainWrapper>(
-            maxCacheSize, true));
+    this.userPipelineMap = Collections.synchronizedMap(new LRUCacheHashMap<>(maxCacheSize, true));

    Configuration serverConf = new Configuration(conf);

@ -181,14 +174,13 @@ protected void serviceStart() throws Exception {
    }

    this.server.start();
-    LOG.info("Router ClientRMService listening on address: "
-        + this.server.getListenerAddress());
+    LOG.info("Router ClientRMService listening on address: {}.", this.server.getListenerAddress());
    super.serviceStart();
  }

  @Override
  protected void serviceStop() throws Exception {
-    LOG.info("Stopping Router ClientRMService");
+    LOG.info("Stopping Router ClientRMService.");
    if (this.server != null) {
      this.server.stop();
    }
@ -201,27 +193,6 @@ public Server getServer() {
    return this.server;
  }

-  /**
-   * Returns the comma separated interceptor class names from the configuration.
-   *
-   * @param conf
-   * @return the interceptor class names as an instance of ArrayList
-   */
-  private List<String> getInterceptorClassNames(Configuration conf) {
-    String configuredInterceptorClassNames =
-        conf.get(YarnConfiguration.ROUTER_CLIENTRM_INTERCEPTOR_CLASS_PIPELINE,
-            YarnConfiguration.DEFAULT_ROUTER_CLIENTRM_INTERCEPTOR_CLASS);
-
-    List<String> interceptorClassNames = new ArrayList<String>();
-    Collection<String> tempList =
-        StringUtils.getStringCollection(configuredInterceptorClassNames);
-    for (String item : tempList) {
-      interceptorClassNames.add(item.trim());
-    }
-
-    return interceptorClassNames;
-  }
-
  @Override
  public GetNewApplicationResponse getNewApplication(
      GetNewApplicationRequest request) throws YarnException, IOException {
@ -507,44 +478,10 @@ protected Map<String, RequestInterceptorChainWrapper> getPipelines() {
  @VisibleForTesting
  protected ClientRequestInterceptor createRequestInterceptorChain() {
    Configuration conf = getConfig();
-
-    List<String> interceptorClassNames = getInterceptorClassNames(conf);
-
-    ClientRequestInterceptor pipeline = null;
-    ClientRequestInterceptor current = null;
-    for (String interceptorClassName : interceptorClassNames) {
-      try {
-        Class<?> interceptorClass = conf.getClassByName(interceptorClassName);
-        if (ClientRequestInterceptor.class.isAssignableFrom(interceptorClass)) {
-          ClientRequestInterceptor interceptorInstance =
-              (ClientRequestInterceptor) ReflectionUtils
-                  .newInstance(interceptorClass, conf);
-          if (pipeline == null) {
-            pipeline = interceptorInstance;
-            current = interceptorInstance;
-            continue;
-          } else {
-            current.setNextInterceptor(interceptorInstance);
-            current = interceptorInstance;
-          }
-        } else {
-          throw new YarnRuntimeException(
-              "Class: " + interceptorClassName + " not instance of "
-                  + ClientRequestInterceptor.class.getCanonicalName());
-        }
-      } catch (ClassNotFoundException e) {
-        throw new YarnRuntimeException(
-            "Could not instantiate ApplicationClientRequestInterceptor: "
-                + interceptorClassName,
-            e);
-      }
-    }
-
-    if (pipeline == null) {
-      throw new YarnRuntimeException(
-          "RequestInterceptor pipeline is not configured in the system");
-    }
-    return pipeline;
+    return RouterServerUtil.createRequestInterceptorChain(conf,
+        YarnConfiguration.ROUTER_CLIENTRM_INTERCEPTOR_CLASS_PIPELINE,
+        YarnConfiguration.DEFAULT_ROUTER_CLIENTRM_INTERCEPTOR_CLASS,
+        ClientRequestInterceptor.class);
  }

  /**
@ -565,15 +502,15 @@ private RequestInterceptorChainWrapper initializePipeline(String user) {
      try {
        // We should init the pipeline instance after it is created and then
        // add to the map, to ensure thread safe.
-        LOG.info("Initializing request processing pipeline for application "
-            + "for the user: {}", user);
+        LOG.info("Initializing request processing pipeline for application for the user: {}.",
+            user);

        ClientRequestInterceptor interceptorChain =
            this.createRequestInterceptorChain();
        interceptorChain.init(user);
        chainWrapper.init(interceptorChain);
      } catch (Exception e) {
-        LOG.error("Init ClientRequestInterceptor error for user: " + user, e);
+        LOG.error("Init ClientRequestInterceptor error for user: {}.", user, e);
        throw e;
      }

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/rmadmin/RouterRMAdminService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/rmadmin/RouterRMAdminService.java
@ -20,10 +20,7 @@

 import java.io.IOException;
 import java.net.InetSocketAddress;
-import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import java.util.Map;

 import org.apache.hadoop.classification.InterfaceAudience.Private;
@ -34,11 +31,8 @@
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.PolicyProvider;
 import org.apache.hadoop.service.AbstractService;
-import org.apache.hadoop.util.ReflectionUtils;
-import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
-import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.apache.hadoop.yarn.ipc.YarnRPC;
 import org.apache.hadoop.yarn.server.api.ResourceManagerAdministrationProtocol;
 import org.apache.hadoop.yarn.server.api.protocolrecords.AddToClusterNodeLabelsRequest;
@ -69,6 +63,7 @@
 import org.apache.hadoop.yarn.server.api.protocolrecords.ReplaceLabelsOnNodeResponse;
 import org.apache.hadoop.yarn.server.api.protocolrecords.UpdateNodeResourceRequest;
 import org.apache.hadoop.yarn.server.api.protocolrecords.UpdateNodeResourceResponse;
+import org.apache.hadoop.yarn.server.router.RouterServerUtil;
 import org.apache.hadoop.yarn.server.router.security.authorize.RouterPolicyProvider;
 import org.apache.hadoop.yarn.util.LRUCacheHashMap;
 import org.slf4j.Logger;
@ -106,7 +101,7 @@ public RouterRMAdminService() {

  @Override
  protected void serviceStart() throws Exception {
-    LOG.info("Starting Router RMAdmin Service");
+    LOG.info("Starting Router RMAdmin Service.");
    Configuration conf = getConfig();
    YarnRPC rpc = YarnRPC.create(conf);
    UserGroupInformation.setConfiguration(conf);
@ -120,9 +115,7 @@ protected void serviceStart() throws Exception {
    int maxCacheSize =
        conf.getInt(YarnConfiguration.ROUTER_PIPELINE_CACHE_MAX_SIZE,
            YarnConfiguration.DEFAULT_ROUTER_PIPELINE_CACHE_MAX_SIZE);
-    this.userPipelineMap = Collections.synchronizedMap(
-        new LRUCacheHashMap<String, RequestInterceptorChainWrapper>(
-            maxCacheSize, true));
+    this.userPipelineMap = Collections.synchronizedMap(new LRUCacheHashMap<>(maxCacheSize, true));

    Configuration serverConf = new Configuration(conf);

@ -139,14 +132,13 @@ protected void serviceStart() throws Exception {
    }

    this.server.start();
-    LOG.info("Router RMAdminService listening on address: "
-        + this.server.getListenerAddress());
+    LOG.info("Router RMAdminService listening on address: {}.", this.server.getListenerAddress());
    super.serviceStart();
  }

  @Override
  protected void serviceStop() throws Exception {
-    LOG.info("Stopping Router RMAdminService");
+    LOG.info("Stopping Router RMAdminService.");
    if (this.server != null) {
      this.server.stop();
    }
@ -164,27 +156,6 @@ public Server getServer() {
    return this.server;
  }

-  /**
-   * Returns the comma separated interceptor class names from the configuration.
-   *
-   * @param conf
-   * @return the interceptor class names as an instance of ArrayList
-   */
-  private List<String> getInterceptorClassNames(Configuration conf) {
-    String configuredInterceptorClassNames =
-        conf.get(YarnConfiguration.ROUTER_RMADMIN_INTERCEPTOR_CLASS_PIPELINE,
-            YarnConfiguration.DEFAULT_ROUTER_RMADMIN_INTERCEPTOR_CLASS);
-
-    List<String> interceptorClassNames = new ArrayList<String>();
-    Collection<String> tempList =
-        StringUtils.getStringCollection(configuredInterceptorClassNames);
-    for (String item : tempList) {
-      interceptorClassNames.add(item.trim());
-    }
-
-    return interceptorClassNames;
-  }
-
  @VisibleForTesting
  protected RequestInterceptorChainWrapper getInterceptorChain()
      throws IOException {
@ -215,45 +186,10 @@ protected Map<String, RequestInterceptorChainWrapper> getPipelines() {
  @VisibleForTesting
  protected RMAdminRequestInterceptor createRequestInterceptorChain() {
    Configuration conf = getConfig();
-
-    List<String> interceptorClassNames = getInterceptorClassNames(conf);
-
-    RMAdminRequestInterceptor pipeline = null;
-    RMAdminRequestInterceptor current = null;
-    for (String interceptorClassName : interceptorClassNames) {
-      try {
-        Class<?> interceptorClass = conf.getClassByName(interceptorClassName);
-        if (RMAdminRequestInterceptor.class
-            .isAssignableFrom(interceptorClass)) {
-          RMAdminRequestInterceptor interceptorInstance =
-              (RMAdminRequestInterceptor) ReflectionUtils
-                  .newInstance(interceptorClass, conf);
-          if (pipeline == null) {
-            pipeline = interceptorInstance;
-            current = interceptorInstance;
-            continue;
-          } else {
-            current.setNextInterceptor(interceptorInstance);
-            current = interceptorInstance;
-          }
-        } else {
-          throw new YarnRuntimeException(
-              "Class: " + interceptorClassName + " not instance of "
-                  + RMAdminRequestInterceptor.class.getCanonicalName());
-        }
-      } catch (ClassNotFoundException e) {
-        throw new YarnRuntimeException(
-            "Could not instantiate RMAdminRequestInterceptor: "
-                + interceptorClassName,
-            e);
-      }
-    }
-
-    if (pipeline == null) {
-      throw new YarnRuntimeException(
-          "RequestInterceptor pipeline is not configured in the system");
-    }
-    return pipeline;
+    return RouterServerUtil.createRequestInterceptorChain(conf,
+        YarnConfiguration.ROUTER_RMADMIN_INTERCEPTOR_CLASS_PIPELINE,
+        YarnConfiguration.DEFAULT_ROUTER_RMADMIN_INTERCEPTOR_CLASS,
+        RMAdminRequestInterceptor.class);
  }

  /**
@ -274,14 +210,14 @@ private RequestInterceptorChainWrapper initializePipeline(String user) {
      try {
        // We should init the pipeline instance after it is created and then
        // add to the map, to ensure thread safe.
-        LOG.info("Initializing request processing pipeline for user: {}", user);
+        LOG.info("Initializing request processing pipeline for user: {}.", user);

        RMAdminRequestInterceptor interceptorChain =
            this.createRequestInterceptorChain();
        interceptorChain.init(user);
        chainWrapper.init(interceptorChain);
      } catch (Exception e) {
-        LOG.error("Init RMAdminRequestInterceptor error for user: " + user, e);
+        LOG.error("Init RMAdminRequestInterceptor error for user: {}.", user, e);
        throw e;
      }

--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/webapp/RouterWebServices.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/webapp/RouterWebServices.java
@ -19,10 +19,7 @@
 package org.apache.hadoop.yarn.server.router.webapp;

 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;

@ -48,11 +45,8 @@
 import org.apache.hadoop.http.JettyUtils;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.AuthorizationException;
-import org.apache.hadoop.util.ReflectionUtils;
-import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
-import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.RMWSConsts;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.RMWebServiceProtocol;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.ActivitiesInfo;
@ -86,6 +80,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.BulkActivitiesInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.SchedulerTypeInfo;
 import org.apache.hadoop.yarn.server.router.Router;
+import org.apache.hadoop.yarn.server.router.RouterServerUtil;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainerInfo;
 import org.apache.hadoop.yarn.server.webapp.dao.ContainersInfo;
 import org.apache.hadoop.yarn.util.LRUCacheHashMap;
@ -136,30 +131,7 @@ public RouterWebServices(final Router router, Configuration conf) {
    int maxCacheSize =
        conf.getInt(YarnConfiguration.ROUTER_PIPELINE_CACHE_MAX_SIZE,
            YarnConfiguration.DEFAULT_ROUTER_PIPELINE_CACHE_MAX_SIZE);
-    this.userPipelineMap = Collections.synchronizedMap(
-        new LRUCacheHashMap<String, RequestInterceptorChainWrapper>(
-            maxCacheSize, true));
-  }
-
-  /**
-   * Returns the comma separated interceptor class names from the configuration.
-   *
-   * @param conf
-   * @return the interceptor class names as an instance of ArrayList
-   */
-  private List<String> getInterceptorClassNames(Configuration config) {
-    String configuredInterceptorClassNames =
-        config.get(YarnConfiguration.ROUTER_WEBAPP_INTERCEPTOR_CLASS_PIPELINE,
-            YarnConfiguration.DEFAULT_ROUTER_WEBAPP_INTERCEPTOR_CLASS);
-
-    List<String> interceptorClassNames = new ArrayList<String>();
-    Collection<String> tempList =
-        StringUtils.getStringCollection(configuredInterceptorClassNames);
-    for (String item : tempList) {
-      interceptorClassNames.add(item.trim());
-    }
-
-    return interceptorClassNames;
+    this.userPipelineMap = Collections.synchronizedMap(new LRUCacheHashMap<>(maxCacheSize, true));
  }

  private void init() {
@ -207,50 +179,16 @@ protected Map<String, RequestInterceptorChainWrapper> getPipelines() {
   */
  @VisibleForTesting
  protected RESTRequestInterceptor createRequestInterceptorChain() {
-
-    List<String> interceptorClassNames = getInterceptorClassNames(conf);
-
-    RESTRequestInterceptor pipeline = null;
-    RESTRequestInterceptor current = null;
-    for (String interceptorClassName : interceptorClassNames) {
-      try {
-        Class<?> interceptorClass = conf.getClassByName(interceptorClassName);
-        if (RESTRequestInterceptor.class.isAssignableFrom(interceptorClass)) {
-          RESTRequestInterceptor interceptorInstance =
-              (RESTRequestInterceptor) ReflectionUtils
-                  .newInstance(interceptorClass, conf);
-          if (pipeline == null) {
-            pipeline = interceptorInstance;
-            current = interceptorInstance;
-            continue;
-          } else {
-            current.setNextInterceptor(interceptorInstance);
-            current = interceptorInstance;
-          }
-        } else {
-          throw new YarnRuntimeException(
-              "Class: " + interceptorClassName + " not instance of "
-                  + RESTRequestInterceptor.class.getCanonicalName());
-        }
-      } catch (ClassNotFoundException e) {
-        throw new YarnRuntimeException(
-            "Could not instantiate RESTRequestInterceptor: "
-                + interceptorClassName,
-            e);
-      }
-    }
-
-    if (pipeline == null) {
-      throw new YarnRuntimeException(
-          "RequestInterceptor pipeline is not configured in the system");
-    }
-    return pipeline;
+    return RouterServerUtil.createRequestInterceptorChain(conf,
+        YarnConfiguration.ROUTER_WEBAPP_INTERCEPTOR_CLASS_PIPELINE,
+        YarnConfiguration.DEFAULT_ROUTER_WEBAPP_INTERCEPTOR_CLASS,
+        RESTRequestInterceptor.class);
  }

  /**
   * Initializes the request interceptor pipeline for the specified user.
   *
-   * @param user
+   * @param user specified user.
   */
  private RequestInterceptorChainWrapper initializePipeline(String user) {
    synchronized (this.userPipelineMap) {
@ -265,14 +203,14 @@ private RequestInterceptorChainWrapper initializePipeline(String user) {
      try {
        // We should init the pipeline instance after it is created and then
        // add to the map, to ensure thread safe.
-        LOG.info("Initializing request processing pipeline for user: {}", user);
+        LOG.info("Initializing request processing pipeline for user: {}.", user);

        RESTRequestInterceptor interceptorChain =
            this.createRequestInterceptorChain();
        interceptorChain.init(user);
        chainWrapper.init(interceptorChain);
      } catch (Exception e) {
-        LOG.error("Init RESTRequestInterceptor error for user: " + user, e);
+        LOG.error("Init RESTRequestInterceptor error for user: {}", user, e);
        throw e;
      }

@ -338,7 +276,7 @@ public ClusterInfo getClusterInfo() {
  @GET
  @Path(RMWSConsts.CLUSTER_USER_INFO)
  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
-          MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
+      MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
  @Override
  public ClusterUserInfo getClusterUserInfo(@Context HttpServletRequest hsr) {
    init();
@ -834,10 +772,12 @@ public Response deleteReservation(ReservationDeleteRequestInfo resContext,
  @Override
  public Response listReservation(
      @QueryParam(RMWSConsts.QUEUE) @DefaultValue(DEFAULT_QUEUE) String queue,
-      @QueryParam(RMWSConsts.RESERVATION_ID) @DefaultValue(DEFAULT_RESERVATION_ID) String reservationId,
+      @QueryParam(RMWSConsts.RESERVATION_ID)
+      @DefaultValue(DEFAULT_RESERVATION_ID) String reservationId,
      @QueryParam(RMWSConsts.START_TIME) @DefaultValue(DEFAULT_START_TIME) long startTime,
      @QueryParam(RMWSConsts.END_TIME) @DefaultValue(DEFAULT_END_TIME) long endTime,
-      @QueryParam(RMWSConsts.INCLUDE_RESOURCE) @DefaultValue(DEFAULT_INCLUDE_RESOURCE) boolean includeResourceAllocations,
+      @QueryParam(RMWSConsts.INCLUDE_RESOURCE)
+      @DefaultValue(DEFAULT_INCLUDE_RESOURCE) boolean includeResourceAllocations,
      @Context HttpServletRequest hsr) throws Exception {
    init();
    RequestInterceptorChainWrapper pipeline = getInterceptorChain(hsr);
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/rmadmin/TestRouterRMAdminService.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/test/java/org/apache/hadoop/yarn/server/router/rmadmin/TestRouterRMAdminService.java
@ -23,7 +23,6 @@
 import java.util.Map;

 import org.apache.hadoop.security.UserGroupInformation;
-import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.api.protocolrecords.AddToClusterNodeLabelsResponse;
 import org.apache.hadoop.yarn.server.api.protocolrecords.CheckForDecommissioningNodesResponse;
 import org.apache.hadoop.yarn.server.api.protocolrecords.RefreshAdminAclsResponse;
@ -185,7 +184,7 @@ public void testRouterRMAdminServiceE2E() throws Exception {
   */
  @Test
  public void testUsersChainMapWithLRUCache()
-      throws YarnException, IOException, InterruptedException {
+      throws IOException, InterruptedException {

    Map<String, RequestInterceptorChainWrapper> pipelines;
    RequestInterceptorChainWrapper chain;