YARN-11490. Reverting YARN-11211 and eliminating the use of DefaultMetricsSystem during configuration validation (#5644)

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

@@ -78,7 +78,7 @@ public synchronized QueueMetrics getUserMetrics(String userName) {
       metrics = new PartitionQueueMetrics(this.metricsSystem, this.queueName,
           null, false, this.conf, this.partition);
       users.put(userName, metrics);
-      registerMetrics(
+      metricsSystem.register(
           pSourceName(partitionJMXStr).append(qSourceName(queueName))
               .append(",user=").append(userName).toString(),
           "Metrics for user '" + userName + "' in queue '" + queueName + "'",

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

@@ -117,6 +117,9 @@ public class QueueMetrics implements MetricsSource {
   @Metric("Reserved CPU in virtual cores") MutableGaugeInt reservedVCores;
   @Metric("# of reserved containers") MutableGaugeInt reservedContainers;
 
+  // INTERNAL ONLY
+  private static final String CONFIGURATION_VALIDATION = "yarn.configuration-validation";
+
   private final MutableGaugeInt[] runningTime;
   private TimeBucketMetrics<ApplicationId> runBuckets;
 
@@ -289,7 +292,7 @@ public synchronized QueueMetrics getUserMetrics(String userName) {
       metrics =
           new QueueMetrics(metricsSystem, queueName, null, false, conf);
       users.put(userName, metrics);
-      registerMetrics(
+      metricsSystem.register(
           sourceName(queueName).append(",user=").append(userName).toString(),
           "Metrics for user '"+ userName +"' in queue '"+ queueName +"'",
           metrics.tag(QUEUE_INFO, queueName).tag(USER_INFO, userName));
@@ -334,13 +337,15 @@ public synchronized QueueMetrics getPartitionQueueMetrics(String partition) {
       QueueMetrics queueMetrics =
           new PartitionQueueMetrics(metricsSystem, this.queueName, parentQueue,
               this.enableUserMetrics, this.conf, partition);
-      registerMetrics(
+      metricsSystem.register(
           pSourceName(partitionJMXStr).append(qSourceName(this.queueName))
               .toString(),
           "Metrics for queue: " + this.queueName,
           queueMetrics.tag(PARTITION_INFO, partitionJMXStr).tag(QUEUE_INFO,
               this.queueName));
-      getQueueMetrics().put(metricName, queueMetrics);
+      if (!isConfigurationValidationSet(conf)) {
+        getQueueMetrics().put(metricName, queueMetrics);
+      }
       registerPartitionMetricsCreation(metricName);
       return queueMetrics;
     } else {
@@ -348,6 +353,26 @@ public synchronized QueueMetrics getPartitionQueueMetrics(String partition) {
     }
   }
 
+  /**
+   * Check whether we are in a configuration validation mode. INTERNAL ONLY.
+   *
+   * @param conf the configuration to check
+   * @return true if
+   */
+  public static boolean isConfigurationValidationSet(Configuration conf) {
+    return conf.getBoolean(CONFIGURATION_VALIDATION, false);
+  }
+
+  /**
+   * Set configuration validation mode. INTERNAL ONLY.
+   *
+   * @param conf the configuration to update
+   * @param value the value for the validation mode
+   */
+  public static void setConfigurationValidation(Configuration conf, boolean value) {
+    conf.setBoolean(CONFIGURATION_VALIDATION, value);
+  }
+
   /**
    * Partition Metrics
    *
@@ -378,7 +403,7 @@ private QueueMetrics getPartitionMetrics(String partition) {
 
       // Register with the MetricsSystems
       if (metricsSystem != null) {
-        registerMetrics(pSourceName(partitionJMXStr).toString(),
+        metricsSystem.register(pSourceName(partitionJMXStr).toString(),
             "Metrics for partition: " + partitionJMXStr,
             (PartitionQueueMetrics) metrics.tag(PARTITION_INFO,
                 partitionJMXStr));
@@ -1359,15 +1384,4 @@ public void setParentQueue(Queue parentQueue) {
       }
     }
   }
-
-  protected void registerMetrics(String sourceName, String desc, QueueMetrics metrics) {
-    MetricsSource source = metricsSystem.getSource(sourceName);
-    // Unregister metrics if a source is already present
-    if (source != null) {
-      LOG.info("Unregistering source " + sourceName);
-      metricsSystem.unregisterSource(sourceName);
-    }
-
-    metricsSystem.register(sourceName, desc, metrics);
-  }
 }

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

@@ -21,11 +21,13 @@
 import java.util.Map;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.metrics2.MetricsSink;
 import org.apache.hadoop.metrics2.MetricsSource;
 import org.apache.hadoop.metrics2.MetricsSystem;
 import org.apache.hadoop.metrics2.annotation.Metric;
 import org.apache.hadoop.metrics2.annotation.Metrics;
 import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
+import org.apache.hadoop.metrics2.lib.MetricsAnnotations;
 import org.apache.hadoop.metrics2.lib.MutableGaugeFloat;
 import org.apache.hadoop.metrics2.lib.MutableGaugeInt;
 import org.apache.hadoop.metrics2.lib.MutableGaugeLong;
@@ -230,9 +232,74 @@ protected void createQueueMetricsForCustomResources() {
     }
   }
 
+  @Metrics(context="dummymetricssystem")
+  public static class DummyMetricsSystemImpl extends MetricsSystem {
+    @Override
+    public MetricsSystem init(String prefix) {
+      return this;
+    }
+
+    @Override
+    public <T> T register(String name, String desc, T source) {
+      MetricsAnnotations.newSourceBuilder(source).build();
+      return source;
+    }
+
+    @Override
+    public void unregisterSource(String name) {
+    }
+
+    @Override
+    public MetricsSource getSource(String name) {
+      return null;
+    }
+
+    @Override
+    public <T extends MetricsSink> T register(String name, String desc, T sink) {
+      return null;
+    }
+
+    @Override
+    public void register(Callback callback) {
+    }
+
+    @Override
+    public void publishMetricsNow() {
+    }
+
+    @Override
+    public boolean shutdown() {
+      return false;
+    }
+
+    @Override
+    public void start() {
+    }
+
+    @Override
+    public void stop() {
+    }
+
+    @Override
+    public void startMetricsMBeans() {
+    }
+
+    @Override
+    public void stopMetricsMBeans() {
+    }
+
+    @Override
+    public String currentConfig() {
+      return null;
+    }
+  }
+
   public synchronized static CSQueueMetrics forQueue(String queueName,
       Queue parent, boolean enableUserMetrics, Configuration conf) {
-    MetricsSystem ms = DefaultMetricsSystem.instance();
+    final boolean isConfigValidation = isConfigurationValidationSet(conf);
+
+    MetricsSystem ms = isConfigValidation
+        ? new DummyMetricsSystemImpl() : DefaultMetricsSystem.instance();
     QueueMetrics metrics = getQueueMetrics().get(queueName);
     if (metrics == null) {
       metrics =
@@ -241,15 +308,14 @@ public synchronized static CSQueueMetrics forQueue(String queueName,
 
       // Register with the MetricsSystems
       if (ms != null) {
-        MetricsSource source = ms.getSource(sourceName(queueName).toString());
-        if (source != null) {
-          ms.unregisterSource(sourceName(queueName).toString());
-        }
         metrics =
             ms.register(sourceName(queueName).toString(), "Metrics for queue: "
                 + queueName, metrics);
       }
-      getQueueMetrics().put(queueName, metrics);
+
+      if (!isConfigValidation) {
+        getQueueMetrics().put(queueName, metrics);
+      }
     }
 
     return (CSQueueMetrics) metrics;
@@ -265,7 +331,7 @@ public synchronized QueueMetrics getUserMetrics(String userName) {
       metrics =
         new CSQueueMetrics(metricsSystem, queueName, null, false, conf);
       users.put(userName, metrics);
-      registerMetrics(
+      metricsSystem.register(
           sourceName(queueName).append(",user=").append(userName).toString(),
           "Metrics for user '" + userName + "' in queue '" + queueName + "'",
           ((CSQueueMetrics) metrics.tag(QUEUE_INFO, queueName)).tag(USER_INFO,

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

@@ -41,8 +41,13 @@ private CapacitySchedulerConfigValidator() {
   }
 
   public static boolean validateCSConfiguration(
-          final Configuration oldConf, final Configuration newConf,
+          final Configuration oldConfParam, final Configuration newConf,
           final RMContext rmContext) throws IOException {
+    // ensure that the oldConf is deep copied
+    Configuration oldConf = new Configuration(oldConfParam);
+    QueueMetrics.setConfigurationValidation(oldConf, true);
+    QueueMetrics.setConfigurationValidation(newConf, true);
+
     CapacityScheduler liveScheduler = (CapacityScheduler) rmContext.getScheduler();
     CapacityScheduler newCs = new CapacityScheduler();
     try {
@@ -56,8 +61,6 @@ public static boolean validateCSConfiguration(
       return true;
     } finally {
       newCs.stop();
-      QueueMetrics.clearQueueMetrics();
-      liveScheduler.resetSchedulerMetrics();
     }
   }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestCapacitySchedulerConfigValidator.java

@@ -19,6 +19,9 @@
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.metrics2.MetricsSource;
+import org.apache.hadoop.metrics2.MetricsSystem;
+import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
 import org.apache.hadoop.thirdparty.com.google.common.collect.ImmutableMap;
 import org.apache.hadoop.yarn.LocalConfigurationProvider;
 import org.apache.hadoop.yarn.api.protocolrecords.ResourceTypes;
@@ -32,6 +35,7 @@
 import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
 import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
 import org.apache.hadoop.yarn.server.resourcemanager.placement.PlacementManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueMetrics;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.util.YarnVersionInfo;
 import org.apache.hadoop.yarn.util.resource.DominantResourceCalculator;
@@ -425,6 +429,98 @@ public void testValidateCSConfigAddALeafQueueValid() throws IOException {
     Assert.assertTrue(isValidConfig);
   }
 
+  @Test
+  public void testValidateDoesNotModifyTheDefaultMetricsSystem() throws Exception {
+    try {
+      YarnConfiguration conf = new YarnConfiguration(CapacitySchedulerConfigGeneratorForTest
+          .createBasicCSConfiguration());
+      conf.setClass(YarnConfiguration.RM_SCHEDULER, CapacityScheduler.class,
+          ResourceScheduler.class);
+      mockRM = new MockRM(conf);
+
+      cs = (CapacityScheduler) mockRM.getResourceScheduler();
+      mockRM.start();
+      cs.start();
+      RMContext rmContext = mockRM.getRMContext();
+      Configuration oldConfig = cs.getConfig();
+
+      final Map<String, QueueMetrics> cache = QueueMetrics.getQueueMetrics();
+      final MetricsSystem ms = DefaultMetricsSystem.instance();
+
+      QueueMetrics origQM1 = cache.get("root.test1");
+      QueueMetrics origQM2 = cache.get("root.test2");
+      Assert.assertNotNull("Original queues should be found in the cache", origQM1);
+      Assert.assertNotNull("Original queues should be found in the cache", origQM2);
+
+      QueueMetrics origPQM1 = cache.get("default.root.test1");
+      QueueMetrics origPQM2 = cache.get("default.root.test2");
+      Assert.assertNotNull("Original queues should be found in the cache (PartitionQueueMetrics)",
+          origPQM1);
+      Assert.assertNotNull("Original queues should be found in the cache (PartitionQueueMetrics)",
+          origPQM2);
+
+      MetricsSource origMS1 =
+          ms.getSource("QueueMetrics,q0=root,q1=test1");
+      MetricsSource origMS2 =
+          ms.getSource("QueueMetrics,q0=root,q1=test2");
+      Assert.assertNotNull("Original queues should be found in the Metrics System",
+          origMS1);
+      Assert.assertNotNull("Original queues should be found in the Metrics System",
+          origMS2);
+
+      MetricsSource origPMS1 = ms
+          .getSource("PartitionQueueMetrics,partition=,q0=root,q1=test1");
+      MetricsSource origPMS2 = ms
+          .getSource("PartitionQueueMetrics,partition=,q0=root,q1=test2");
+      Assert.assertNotNull(
+          "Original queues should be found in Metrics System (PartitionQueueMetrics)", origPMS1);
+      Assert.assertNotNull(
+          "Original queues should be found in Metrics System (PartitionQueueMetrics)", origPMS2);
+
+      Configuration newConfig = new Configuration(oldConfig);
+      newConfig
+          .set("yarn.scheduler.capacity.root.queues", "test1, test2, test3");
+      newConfig
+          .set("yarn.scheduler.capacity.root.test3.state", "RUNNING");
+      newConfig
+          .set("yarn.scheduler.capacity.root.test3.capacity", "30");
+      newConfig
+          .set("yarn.scheduler.capacity.root.test1.capacity", "20");
+
+      boolean isValidConfig = CapacitySchedulerConfigValidator
+          .validateCSConfiguration(oldConfig, newConfig, rmContext);
+      Assert.assertTrue(isValidConfig);
+
+      Assert.assertFalse("Validated new queue should not be in the cache",
+          cache.containsKey("root.test3"));
+      Assert.assertFalse("Validated new queue should not be in the cache (PartitionQueueMetrics)",
+          cache.containsKey("default.root.test3"));
+      Assert.assertNull("Validated new queue should not be in the Metrics System",
+          ms.getSource("QueueMetrics,q0=root,q1=test3"));
+      Assert.assertNull(
+          "Validated new queue should not be in Metrics System (PartitionQueueMetrics)",
+          ms
+              .getSource("PartitionQueueMetrics,partition=,q0=root,q1=test3"));
+
+      // Config validation should not change the existing
+      // objects in the cache and the metrics system
+      Assert.assertEquals(origQM1, cache.get("root.test1"));
+      Assert.assertEquals(origQM2, cache.get("root.test2"));
+      Assert.assertEquals(origPQM1, cache.get("default.root.test1"));
+      Assert.assertEquals(origPQM1, cache.get("default.root.test1"));
+      Assert.assertEquals(origMS1,
+          ms.getSource("QueueMetrics,q0=root,q1=test1"));
+      Assert.assertEquals(origMS2,
+          ms.getSource("QueueMetrics,q0=root,q1=test2"));
+      Assert.assertEquals(origPMS1,
+          ms.getSource("PartitionQueueMetrics,partition=,q0=root,q1=test1"));
+      Assert.assertEquals(origPMS2,
+          ms.getSource("PartitionQueueMetrics,partition=,q0=root,q1=test2"));
+    } finally {
+      mockRM.stop();
+    }
+  }
+
   /**
    * Delete a running queue.
    */