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.connect.runtime.distributed;
  
  import org.apache.kafka.clients.ApiVersions;
  import org.apache.kafka.clients.ClientUtils;
  import org.apache.kafka.clients.CommonClientConfigs;
  import org.apache.kafka.clients.GroupRebalanceConfig;
  import org.apache.kafka.clients.Metadata;
  import org.apache.kafka.clients.MetadataRecoveryStrategy;
  import org.apache.kafka.clients.NetworkClient;
  import org.apache.kafka.clients.consumer.CloseOptions;
  import org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient;
  import org.apache.kafka.common.KafkaException;
  import org.apache.kafka.common.internals.ClusterResourceListeners;
  import org.apache.kafka.common.metrics.KafkaMetricsContext;
  import org.apache.kafka.common.metrics.MetricConfig;
  import org.apache.kafka.common.metrics.Metrics;
  import org.apache.kafka.common.metrics.MetricsContext;
  import org.apache.kafka.common.metrics.MetricsReporter;
  import org.apache.kafka.common.network.ChannelBuilder;
  import org.apache.kafka.common.network.Selector;
  import org.apache.kafka.common.utils.AppInfoParser;
  import org.apache.kafka.common.utils.LogContext;
  import org.apache.kafka.common.utils.Time;
  import org.apache.kafka.common.utils.Utils;
  import org.apache.kafka.connect.runtime.WorkerConfig;
  import org.apache.kafka.connect.storage.ConfigBackingStore;
  import org.apache.kafka.connect.util.ConnectorTaskId;
  
  import org.slf4j.Logger;
  
  import java.net.InetSocketAddress;
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  import java.util.function.Supplier;
  
  import static org.apache.kafka.common.utils.Utils.UncheckedCloseable;
  
  /**
   * This class manages the coordination process with brokers for the Connect cluster group membership. It ties together
   * the Coordinator, which implements the group member protocol, with all the other pieces needed to drive the connection
   * to the group coordinator broker. This isolates all the networking to a single thread managed by this class, with
   * higher level operations in response to group membership events being handled by the herder.
   */
  public class WorkerGroupMember {
      private static final String JMX_PREFIX = "kafka.connect";
  
      private final Logger log;
      private final String clientId;
      private final ConsumerNetworkClient client;
      private final Metrics metrics;
      private final WorkerCoordinator coordinator;
  
      private boolean stopped = false;
  
      public WorkerGroupMember(DistributedConfig config,
                               String restUrl,
                               ConfigBackingStore configStorage,
                               WorkerRebalanceListener listener,
                               Time time,
                               String clientId,
                               LogContext logContext) {
          try {
              this.clientId = clientId;
              this.log = logContext.logger(WorkerGroupMember.class);
  
              Map<String, String> metricsTags = new LinkedHashMap<>();
              metricsTags.put("client-id", clientId);
              MetricConfig metricConfig = new MetricConfig().samples(config.getInt(CommonClientConfigs.METRICS_NUM_SAMPLES_CONFIG))
                      .timeWindow(config.getLong(CommonClientConfigs.METRICS_SAMPLE_WINDOW_MS_CONFIG), TimeUnit.MILLISECONDS)
                      .tags(metricsTags);
              List<MetricsReporter> reporters = CommonClientConfigs.metricsReporters(clientId, config);
  
              Map<String, Object> contextLabels = new HashMap<>(config.originalsWithPrefix(CommonClientConfigs.METRICS_CONTEXT_PREFIX));
              contextLabels.put(WorkerConfig.CONNECT_KAFKA_CLUSTER_ID, config.kafkaClusterId());
              contextLabels.put(WorkerConfig.CONNECT_GROUP_ID, config.getString(DistributedConfig.GROUP_ID_CONFIG));
              MetricsContext metricsContext = new KafkaMetricsContext(JMX_PREFIX, contextLabels);
  
              this.metrics = new Metrics(metricConfig, reporters, time, metricsContext);
              long retryBackoffMs = config.getLong(CommonClientConfigs.RETRY_BACKOFF_MS_CONFIG);
              long retryBackoffMaxMs = config.getLong(CommonClientConfigs.RETRY_BACKOFF_MAX_MS_CONFIG);
              Metadata metadata = new Metadata(retryBackoffMs, retryBackoffMaxMs, config.getLong(CommonClientConfigs.METADATA_MAX_AGE_CONFIG),
                      logContext, new ClusterResourceListeners());
              List<InetSocketAddress> addresses = ClientUtils.parseAndValidateAddresses(
                      config.getList(CommonClientConfigs.BOOTSTRAP_SERVERS_CONFIG),
                      config.getString(CommonClientConfigs.CLIENT_DNS_LOOKUP_CONFIG));
              metadata.bootstrap(addresses);
              String metricGrpPrefix = "connect";
              ChannelBuilder channelBuilder = ClientUtils.createChannelBuilder(config, time, logContext);
              NetworkClient netClient = new NetworkClient(
                      new Selector(config.getLong(CommonClientConfigs.CONNECTIONS_MAX_IDLE_MS_CONFIG), metrics, time, metricGrpPrefix, channelBuilder, logContext),
                      metadata,
                      clientId,
                      100, // a fixed large enough value will suffice
                      config.getLong(CommonClientConfigs.RECONNECT_BACKOFF_MS_CONFIG),
                      config.getLong(CommonClientConfigs.RECONNECT_BACKOFF_MAX_MS_CONFIG),
                      config.getInt(CommonClientConfigs.SEND_BUFFER_CONFIG),
                      config.getInt(CommonClientConfigs.RECEIVE_BUFFER_CONFIG),
                      config.getInt(CommonClientConfigs.REQUEST_TIMEOUT_MS_CONFIG),
                      config.getLong(CommonClientConfigs.SOCKET_CONNECTION_SETUP_TIMEOUT_MS_CONFIG),
                      config.getLong(CommonClientConfigs.SOCKET_CONNECTION_SETUP_TIMEOUT_MAX_MS_CONFIG),
                      time,
                      true,
                      new ApiVersions(),
                      logContext,
                      config.getLong(CommonClientConfigs.METADATA_RECOVERY_REBOOTSTRAP_TRIGGER_MS_CONFIG),
                      MetadataRecoveryStrategy.forName(config.getString(CommonClientConfigs.METADATA_RECOVERY_STRATEGY_CONFIG))
              );
              this.client = new ConsumerNetworkClient(
                      logContext,
                      netClient,
                      metadata,
                      time,
                      retryBackoffMs,
                      config.getInt(CommonClientConfigs.REQUEST_TIMEOUT_MS_CONFIG),
                      Integer.MAX_VALUE);
              this.coordinator = new WorkerCoordinator(
                      new GroupRebalanceConfig(config, GroupRebalanceConfig.ProtocolType.CONNECT),
                      logContext,
                      this.client,
                      metrics,
                      metricGrpPrefix,
                      time,
                      restUrl,
                      configStorage,
                      listener,
                      ConnectProtocolCompatibility.compatibility(config.getString(DistributedConfig.CONNECT_PROTOCOL_CONFIG)),
                      config.getInt(DistributedConfig.SCHEDULED_REBALANCE_MAX_DELAY_MS_CONFIG));
  
              AppInfoParser.registerAppInfo(JMX_PREFIX, clientId, metrics, time.milliseconds());
              log.debug("Connect group member created");
          } catch (Throwable t) {
              // call close methods if internal objects are already constructed
              // this is to prevent resource leak. see KAFKA-2121
              stop(true);
              // now propagate the exception
              throw new KafkaException("Failed to construct kafka consumer", t);
          }
      }
  
      public void stop() {
          if (stopped) return;
          stop(false);
      }
  
      /**
       * Ensure that the connection to the broker coordinator is up and that the worker is an
       * active member of the group.
       */
      public void ensureActive(Supplier<UncheckedCloseable> onPoll) {
          coordinator.poll(0, onPoll);
      }
  
      public void poll(long timeout, Supplier<UncheckedCloseable> onPoll) {
          if (timeout < 0)
              throw new IllegalArgumentException("Timeout must not be negative");
          coordinator.poll(timeout, onPoll);
      }
  
      /**
       * Interrupt any running poll() calls, causing a WakeupException to be thrown in the thread invoking that method.
       */
      public void wakeup() {
          this.client.wakeup();
      }
  
      /**
       * Get the member ID of this worker in the group of workers.
       * <p>
       * This ID is the unique member ID automatically generated.
       *
       * @return the member ID
       */
      public String memberId() {
          return coordinator.memberId();
      }
  
      public void requestRejoin() {
          coordinator.requestRejoin("connect worker requested rejoin");
      }
  
      public void maybeLeaveGroup(String leaveReason) {
          coordinator.maybeLeaveGroup(CloseOptions.GroupMembershipOperation.LEAVE_GROUP, leaveReason);
      }
  
      public String ownerUrl(String connector) {
          return coordinator.ownerUrl(connector);
      }
  
      public String ownerUrl(ConnectorTaskId task) {
          return coordinator.ownerUrl(task);
      }
  
      /**
       * Get the version of the connect protocol that is currently active in the group of workers.
       *
       * @return the current connect protocol version
       */
      public short currentProtocolVersion() {
          return coordinator.currentProtocolVersion();
      }
  
      public void revokeAssignment(ExtendedAssignment assignment) {
          coordinator.revokeAssignment(assignment);
      }
  
      private void stop(boolean swallowException) {
          log.trace("Stopping the Connect group member.");
          AtomicReference<Throwable> firstException = new AtomicReference<>();
          this.stopped = true;
          Utils.closeQuietly(coordinator, "coordinator", firstException);
          Utils.closeQuietly(metrics, "consumer metrics", firstException);
          Utils.closeQuietly(client, "consumer network client", firstException);
          AppInfoParser.unregisterAppInfo(JMX_PREFIX, clientId, metrics);
          if (firstException.get() != null && !swallowException)
              throw new KafkaException("Failed to stop the Connect group member", firstException.get());
          else
              log.debug("The Connect group member has stopped.");
      }
  
      // Visible for testing
      Metrics metrics() {
          return this.metrics;
      }
  }
  