content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.kafka.controller.metrics;
  
  import org.apache.kafka.metadata.BrokerRegistration;
  import org.apache.kafka.server.metrics.KafkaYammerMetrics;
  
  import com.yammer.metrics.core.Gauge;
  import com.yammer.metrics.core.Meter;
  import com.yammer.metrics.core.MetricName;
  import com.yammer.metrics.core.MetricsRegistry;
  
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import static org.apache.kafka.controller.metrics.BrokerRegistrationState.getBrokerRegistrationState;
  
  /**
   * These are the metrics which are managed by the ControllerServer class. They generally pertain to
   * aspects of the metadata, like how many topics or partitions we have.
   * All of these except MetadataErrorCount are managed by ControllerMetadataMetricsPublisher.
   *
   * IMPORTANT: Metrics which are managed by the QuorumController class itself should go in
   * {@link org.apache.kafka.controller.metrics.QuorumControllerMetrics}, not here.
   */
  public final class ControllerMetadataMetrics implements AutoCloseable {
      private static final MetricName FENCED_BROKER_COUNT = getMetricName(
          "KafkaController", "FencedBrokerCount");
      private static final MetricName ACTIVE_BROKER_COUNT = getMetricName(
          "KafkaController", "ActiveBrokerCount");
      private static final MetricName CONTROLLED_SHUTDOWN_BROKER_COUNT = getMetricName(
          "KafkaController", "ControlledShutdownBrokerCount"
      );
      private static final String BROKER_REGISTRATION_STATE_METRIC_NAME = "BrokerRegistrationState";
      private static final String BROKER_ID_TAG = "broker";
      private static final MetricName GLOBAL_TOPIC_COUNT = getMetricName(
          "KafkaController", "GlobalTopicCount");
      private static final MetricName GLOBAL_PARTITION_COUNT = getMetricName(
          "KafkaController", "GlobalPartitionCount");
      private static final MetricName OFFLINE_PARTITION_COUNT = getMetricName(
          "KafkaController", "OfflinePartitionsCount");
      private static final MetricName PREFERRED_REPLICA_IMBALANCE_COUNT = getMetricName(
          "KafkaController", "PreferredReplicaImbalanceCount");
      private static final MetricName METADATA_ERROR_COUNT = getMetricName(
          "KafkaController", "MetadataErrorCount");
      private static final MetricName UNCLEAN_LEADER_ELECTIONS_PER_SEC = getMetricName(
          "ControllerStats", "UncleanLeaderElectionsPerSec");
      private static final MetricName ELECTION_FROM_ELIGIBLE_LEADER_REPLICAS_PER_SEC = getMetricName(
          "ControllerStats", "ElectionFromEligibleLeaderReplicasPerSec");
      private static final MetricName IGNORED_STATIC_VOTERS = getMetricName(
          "KafkaController", "IgnoredStaticVoters");
  
      private final Optional<MetricsRegistry> registry;
      private final AtomicInteger fencedBrokerCount = new AtomicInteger(0);
      private final AtomicInteger activeBrokerCount = new AtomicInteger(0);
      private final AtomicInteger controllerShutdownBrokerCount = new AtomicInteger(0);
      private final Map<Integer, Integer> brokerRegistrationStates = new ConcurrentHashMap<>();
      private final AtomicInteger globalTopicCount = new AtomicInteger(0);
      private final AtomicInteger globalPartitionCount = new AtomicInteger(0);
      private final AtomicInteger offlinePartitionCount = new AtomicInteger(0);
      private final AtomicInteger preferredReplicaImbalanceCount = new AtomicInteger(0);
      private final AtomicInteger metadataErrorCount = new AtomicInteger(0);
      private Optional<Meter> uncleanLeaderElectionMeter = Optional.empty();
      private Optional<Meter> electionFromEligibleLeaderReplicasMeter = Optional.empty();
      private final AtomicBoolean ignoredStaticVoters = new AtomicBoolean(false);
  
      /**
       * Create a new ControllerMetadataMetrics object.
       *
       * @param registry The metrics registry, or Optional.empty if this is a test and we don't have one.
       */
      public ControllerMetadataMetrics(Optional<MetricsRegistry> registry) {
          this.registry = registry;
          registry.ifPresent(r -> r.newGauge(FENCED_BROKER_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return fencedBrokerCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(ACTIVE_BROKER_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return activeBrokerCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(CONTROLLED_SHUTDOWN_BROKER_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return controlledShutdownBrokerCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(GLOBAL_TOPIC_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return globalTopicCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(GLOBAL_PARTITION_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return globalPartitionCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(OFFLINE_PARTITION_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return offlinePartitionCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(PREFERRED_REPLICA_IMBALANCE_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return preferredReplicaImbalanceCount();
              }
          }));
          registry.ifPresent(r -> r.newGauge(METADATA_ERROR_COUNT, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return metadataErrorCount();
              }
          }));
          registry.ifPresent(r -> uncleanLeaderElectionMeter =
                  Optional.of(registry.get().newMeter(UNCLEAN_LEADER_ELECTIONS_PER_SEC, "elections", TimeUnit.SECONDS)));
          registry.ifPresent(r -> electionFromEligibleLeaderReplicasMeter =
                  Optional.of(registry.get().newMeter(ELECTION_FROM_ELIGIBLE_LEADER_REPLICAS_PER_SEC, "elections", TimeUnit.SECONDS)));
  
          registry.ifPresent(r -> r.newGauge(IGNORED_STATIC_VOTERS, new Gauge<Integer>() {
              @Override
              public Integer value() {
                  return ignoredStaticVoters() ? 1 : 0;
              }
          }));
      }
  
      public void addBrokerRegistrationStateMetric(int brokerId) {
          registry.ifPresent(r -> r.newGauge(
              getBrokerIdTagMetricName(
                  "KafkaController",
                  BROKER_REGISTRATION_STATE_METRIC_NAME,
                  brokerId
              ),
              new Gauge<Integer>() {
                  @Override
                  public Integer value() {
                      return brokerRegistrationState(brokerId);
                  }
              }
          ));
      }
  
      public void removeBrokerRegistrationStateMetric(int brokerId) {
          registry.ifPresent(r -> r.removeMetric(
              getBrokerIdTagMetricName(
                  "KafkaController",
                  BROKER_REGISTRATION_STATE_METRIC_NAME,
                  brokerId
              )
          ));
      }
  
      public Optional<MetricsRegistry> registry() {
          return registry;
      }
  
      public void setFencedBrokerCount(int brokerCount) {
          this.fencedBrokerCount.set(brokerCount);
      }
  
      public void addToFencedBrokerCount(int brokerCountDelta) {
          this.fencedBrokerCount.addAndGet(brokerCountDelta);
      }
  
      public int fencedBrokerCount() {
          return this.fencedBrokerCount.get();
      }
  
      public void setActiveBrokerCount(int brokerCount) {
          this.activeBrokerCount.set(brokerCount);
      }
  
      public void addToActiveBrokerCount(int brokerCountDelta) {
          this.activeBrokerCount.addAndGet(brokerCountDelta);
      }
  
      public int activeBrokerCount() {
          return this.activeBrokerCount.get();
      }
  
      public void setControlledShutdownBrokerCount(int brokerCount) {
          this.controllerShutdownBrokerCount.set(brokerCount);
      }
  
      public void addToControlledShutdownBrokerCount(int brokerCountDelta) {
          this.controllerShutdownBrokerCount.addAndGet(brokerCountDelta);
      }
  
      public int controlledShutdownBrokerCount() {
          return this.controllerShutdownBrokerCount.get();
      }
  
      public void setBrokerRegistrationState(int brokerId, BrokerRegistration brokerRegistration) {
          // if the broker is unregistered, remove the metric and state
          if (brokerRegistration == null) {
              removeBrokerRegistrationStateMetric(brokerId);
              brokerRegistrationStates.remove(brokerId);
              return;
          }
          BrokerRegistrationState brokerState = getBrokerRegistrationState(brokerRegistration);
          brokerRegistrationStates.put(brokerId, brokerState.state());
      }
  
      public int brokerRegistrationState(int brokerId) {
          return this.brokerRegistrationStates.getOrDefault(
              brokerId,
              BrokerRegistrationState.UNREGISTERED.state()
          );
      }
      
      public void setGlobalTopicCount(int topicCount) {
          this.globalTopicCount.set(topicCount);
      }
  
      public void addToGlobalTopicCount(int topicCountDelta) {
          this.globalTopicCount.addAndGet(topicCountDelta);
      }
  
      public int globalTopicCount() {
          return this.globalTopicCount.get();
      }
  
      public void setGlobalPartitionCount(int partitionCount) {
          this.globalPartitionCount.set(partitionCount);
      }
  
      public void addToGlobalPartitionCount(int partitionCountDelta) {
          this.globalPartitionCount.addAndGet(partitionCountDelta);
      }
  
      public int globalPartitionCount() {
          return this.globalPartitionCount.get();
      }
  
      public void setOfflinePartitionCount(int offlinePartitions) {
          this.offlinePartitionCount.set(offlinePartitions);
      }
  
      public void addToOfflinePartitionCount(int offlinePartitionsDelta) {
          this.offlinePartitionCount.addAndGet(offlinePartitionsDelta);
      }
  
      public int offlinePartitionCount() {
          return this.offlinePartitionCount.get();
      }
  
      public void setPreferredReplicaImbalanceCount(int replicaImbalances) {
          this.preferredReplicaImbalanceCount.set(replicaImbalances);
      }
  
      public void addToPreferredReplicaImbalanceCount(int replicaImbalancesCount) {
          this.preferredReplicaImbalanceCount.addAndGet(replicaImbalancesCount);
      }
  
      public int preferredReplicaImbalanceCount() {
          return this.preferredReplicaImbalanceCount.get();
      }
  
      public void incrementMetadataErrorCount() {
          this.metadataErrorCount.getAndIncrement();
      }
  
      public int metadataErrorCount() {
          return this.metadataErrorCount.get();
      }
      
      public void updateUncleanLeaderElection(int count) {
          this.uncleanLeaderElectionMeter.ifPresent(m -> m.mark(count));
      }
  
      public void updateElectionFromEligibleLeaderReplicasCount(int count) {
          this.electionFromEligibleLeaderReplicasMeter.ifPresent(m -> m.mark(count));
      }
  
      public void setIgnoredStaticVoters(boolean ignored) {
          ignoredStaticVoters.set(ignored);
      }
  
      public boolean ignoredStaticVoters() {
          return ignoredStaticVoters.get();
      }
  
      @Override
      public void close() {
          registry.ifPresent(r -> List.of(
              FENCED_BROKER_COUNT,
              ACTIVE_BROKER_COUNT,
              CONTROLLED_SHUTDOWN_BROKER_COUNT,
              GLOBAL_TOPIC_COUNT,
              GLOBAL_PARTITION_COUNT,
              OFFLINE_PARTITION_COUNT,
              PREFERRED_REPLICA_IMBALANCE_COUNT,
              METADATA_ERROR_COUNT,
              UNCLEAN_LEADER_ELECTIONS_PER_SEC,
              ELECTION_FROM_ELIGIBLE_LEADER_REPLICAS_PER_SEC,
              IGNORED_STATIC_VOTERS
          ).forEach(r::removeMetric));
          for (int brokerId : brokerRegistrationStates.keySet()) {
              removeBrokerRegistrationStateMetric(brokerId);
          }
      }
  
      private static MetricName getMetricName(String type, String name) {
          return KafkaYammerMetrics.getMetricName("kafka.controller", type, name);
      }
  
      private static MetricName getBrokerIdTagMetricName(String type, String name, int brokerId) {
          LinkedHashMap<String, String> brokerIdTag = new LinkedHashMap<>();
          brokerIdTag.put(BROKER_ID_TAG, Integer.toString(brokerId));
          return KafkaYammerMetrics.getMetricName("kafka.controller", type, name, brokerIdTag);
      }
  }
  