HADOOP-17795. Provide fallbacks for callqueue.impl and scheduler.impl (#3192)

Reviewed-by: Wei-Chiu Chuang <weichiu@apache.org>
Signed-off-by: Takanobu Asanuma <tasanuma@apache.org>

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/Server.java

@@ -714,6 +714,7 @@ private String getQueueClassPrefix() {
     return CommonConfigurationKeys.IPC_NAMESPACE + "." + port;
   }
 
+  @Deprecated
   static Class<? extends BlockingQueue<Call>> getQueueClass(
       String prefix, Configuration conf) {
     String name = prefix + "." + CommonConfigurationKeys.IPC_CALLQUEUE_IMPL_KEY;
@@ -721,6 +722,32 @@ static Class<? extends BlockingQueue<Call>> getQueueClass(
     return CallQueueManager.convertQueueClass(queueClass, Call.class);
   }
 
+  /**
+   * Return class configured by property 'ipc.<port>.callqueue.impl' if it is
+   * present. If the config is not present, default config (without port) is
+   * used to derive class i.e 'ipc.callqueue.impl', and derived class is
+   * returned if class value is present and valid. If default config is also
+   * not present, default class {@link LinkedBlockingQueue} is returned.
+   *
+   * @param namespace Namespace "ipc".
+   * @param port Server's listener port.
+   * @param conf Configuration properties.
+   * @return Class returned based on configuration.
+   */
+  static Class<? extends BlockingQueue<Call>> getQueueClass(
+      String namespace, int port, Configuration conf) {
+    String nameWithPort = namespace + "." + port + "."
+        + CommonConfigurationKeys.IPC_CALLQUEUE_IMPL_KEY;
+    String nameWithoutPort = namespace + "."
+        + CommonConfigurationKeys.IPC_CALLQUEUE_IMPL_KEY;
+    Class<?> queueClass = conf.getClass(nameWithPort, null);
+    if(queueClass == null) {
+      queueClass = conf.getClass(nameWithoutPort, LinkedBlockingQueue.class);
+    }
+    return CallQueueManager.convertQueueClass(queueClass, Call.class);
+  }
+
+  @Deprecated
   static Class<? extends RpcScheduler> getSchedulerClass(
       String prefix, Configuration conf) {
     String schedulerKeyname = prefix + "." + CommonConfigurationKeys
@@ -746,6 +773,51 @@ static Class<? extends RpcScheduler> getSchedulerClass(
     return CallQueueManager.convertSchedulerClass(schedulerClass);
   }
 
+  /**
+   * Return class configured by property 'ipc.<port>.scheduler.impl' if it is
+   * present. If the config is not present, and if property
+   * 'ipc.<port>.callqueue.impl' represents FairCallQueue class,
+   * return DecayRpcScheduler. If config 'ipc.<port>.callqueue.impl'
+   * does not have value FairCallQueue, default config (without port) is used
+   * to derive class i.e 'ipc.scheduler.impl'. If default config is also not
+   * present, default class {@link DefaultRpcScheduler} is returned.
+   *
+   * @param namespace Namespace "ipc".
+   * @param port Server's listener port.
+   * @param conf Configuration properties.
+   * @return Class returned based on configuration.
+   */
+  static Class<? extends RpcScheduler> getSchedulerClass(
+      String namespace, int port, Configuration conf) {
+    String schedulerKeyNameWithPort = namespace + "." + port + "."
+        + CommonConfigurationKeys.IPC_SCHEDULER_IMPL_KEY;
+    String schedulerKeyNameWithoutPort = namespace + "."
+        + CommonConfigurationKeys.IPC_SCHEDULER_IMPL_KEY;
+
+    Class<?> schedulerClass = conf.getClass(schedulerKeyNameWithPort, null);
+    // Patch the configuration for legacy fcq configuration that does not have
+    // a separate scheduler setting
+    if (schedulerClass == null) {
+      String queueKeyNameWithPort = namespace + "." + port + "."
+          + CommonConfigurationKeys.IPC_CALLQUEUE_IMPL_KEY;
+      Class<?> queueClass = conf.getClass(queueKeyNameWithPort, null);
+      if (queueClass != null) {
+        if (queueClass.getCanonicalName().equals(
+            FairCallQueue.class.getCanonicalName())) {
+          conf.setClass(schedulerKeyNameWithPort, DecayRpcScheduler.class,
+              RpcScheduler.class);
+        }
+      }
+    }
+
+    schedulerClass = conf.getClass(schedulerKeyNameWithPort, null);
+    if (schedulerClass == null) {
+      schedulerClass = conf.getClass(schedulerKeyNameWithoutPort,
+          DefaultRpcScheduler.class);
+    }
+    return CallQueueManager.convertSchedulerClass(schedulerClass);
+  }
+
   /*
    * Refresh the call queue
    */
@@ -755,8 +827,10 @@ public synchronized void refreshCallQueue(Configuration conf) {
     this.maxQueueSize = handlerCount * conf.getInt(
         CommonConfigurationKeys.IPC_SERVER_HANDLER_QUEUE_SIZE_KEY,
         CommonConfigurationKeys.IPC_SERVER_HANDLER_QUEUE_SIZE_DEFAULT);
-    callQueue.swapQueue(getSchedulerClass(prefix, conf),
-        getQueueClass(prefix, conf), maxQueueSize, prefix, conf);
+    callQueue.swapQueue(
+        getSchedulerClass(CommonConfigurationKeys.IPC_NAMESPACE, port, conf),
+        getQueueClass(CommonConfigurationKeys.IPC_NAMESPACE, port, conf),
+        maxQueueSize, prefix, conf);
     callQueue.setClientBackoffEnabled(getClientBackoffEnable(prefix, conf));
   }
 
@@ -3107,8 +3181,9 @@ protected Server(String bindAddress, int port,
 
     // Setup appropriate callqueue
     final String prefix = getQueueClassPrefix();
-    this.callQueue = new CallQueueManager<Call>(getQueueClass(prefix, conf),
-        getSchedulerClass(prefix, conf),
+    this.callQueue = new CallQueueManager<>(
+        getQueueClass(CommonConfigurationKeys.IPC_NAMESPACE, port, conf),
+        getSchedulerClass(CommonConfigurationKeys.IPC_NAMESPACE, port, conf),
         getClientBackoffEnable(prefix, conf), maxQueueSize, prefix, conf);
 
     this.secretManager = (SecretManager<TokenIdentifier>) secretManager;

hadoop-common-project/hadoop-common/src/main/resources/core-default.xml

@@ -2514,6 +2514,21 @@
   </description>
 </property>
 
+<property>
+  <name>ipc.callqueue.impl</name>
+  <value>java.util.concurrent.LinkedBlockingQueue</value>
+  <description>
+    The fully qualified name of a class to use as the implementation
+    of a call queue. The default implementation is
+    java.util.concurrent.LinkedBlockingQueue (FIFO queue).
+    Use org.apache.hadoop.ipc.FairCallQueue for the Fair Call Queue.
+    This config is fallback config for ipc.[port_number].callqueue.impl.
+    If call queue is not defined at port level, this default
+    config is used and hence, this is fallback config to
+    config with port.
+  </description>
+</property>
+
 <property>
   <name>ipc.[port_number].scheduler.impl</name>
   <value>org.apache.hadoop.ipc.DefaultRpcScheduler</value>
@@ -2527,6 +2542,24 @@
   </description>
 </property>
 
+<property>
+  <name>ipc.scheduler.impl</name>
+  <value>org.apache.hadoop.ipc.DefaultRpcScheduler</value>
+  <description>
+    The fully qualified name of a class to use as the
+    implementation of the scheduler. The default implementation is
+    org.apache.hadoop.ipc.DefaultRpcScheduler (no-op scheduler) when
+    not using FairCallQueue. If using FairCallQueue, defaults to
+    org.apache.hadoop.ipc.DecayRpcScheduler. Use
+    org.apache.hadoop.ipc.DecayRpcScheduler in conjunction
+    with the Fair Call Queue.
+    This config is fallback config for ipc.[port_number].scheduler.impl.
+    If scheduler queue is not defined at port level, this default
+    config is used and hence, this is fallback config to
+    config with port.
+  </description>
+</property>
+
 <property>
   <name>ipc.[port_number].scheduler.priority.levels</name>
   <value>4</value>

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/conf/TestCommonConfigurationFields.java

@@ -157,7 +157,9 @@ public void initializeMemberVariables() {
     // FairCallQueue configs that includes dynamic ports in its keys
     xmlPropsToSkipCompare.add("ipc.[port_number].backoff.enable");
     xmlPropsToSkipCompare.add("ipc.[port_number].callqueue.impl");
+    xmlPropsToSkipCompare.add("ipc.callqueue.impl");
     xmlPropsToSkipCompare.add("ipc.[port_number].scheduler.impl");
+    xmlPropsToSkipCompare.add("ipc.scheduler.impl");
     xmlPropsToSkipCompare.add("ipc.[port_number].scheduler.priority.levels");
     xmlPropsToSkipCompare.add(
         "ipc.[port_number].faircallqueue.multiplexer.weights");

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/TestCallQueueManager.java

@@ -218,7 +218,8 @@ public void testFcqBackwardCompatibility() throws InterruptedException {
 
     // Specify only Fair Call Queue without a scheduler
     // Ensure the DecayScheduler will be added to avoid breaking.
-    Class<? extends RpcScheduler> scheduler = Server.getSchedulerClass(ns,
+    Class<? extends RpcScheduler> scheduler =
+        Server.getSchedulerClass(CommonConfigurationKeys.IPC_NAMESPACE, 0,
         conf);
     assertTrue(scheduler.getCanonicalName().
         equals("org.apache.hadoop.ipc.DecayRpcScheduler"));
@@ -250,8 +251,8 @@ public void testSchedulerWithoutFCQ() throws InterruptedException {
         "LinkedBlockingQueue"));
 
     manager = new CallQueueManager<FakeCall>(queue,
-        Server.getSchedulerClass(ns, conf), false,
-        3, "", conf);
+        Server.getSchedulerClass(CommonConfigurationKeys.IPC_NAMESPACE, 0,
+            conf), false, 3, "", conf);
 
     // LinkedBlockingQueue with a capacity of 3 can put 3 calls
     assertCanPut(manager, 3, 3);