/**
    * 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.hadoop.hbase;
  
  import java.util.Map;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.executor.ExecutorService;
  import org.apache.hadoop.hbase.executor.ExecutorService.ExecutorStatus;
  import org.apache.hadoop.hbase.regionserver.MetricsRegionServerSource;
  import org.apache.hadoop.hbase.regionserver.MetricsRegionServerSourceImpl;
  import org.apache.hadoop.hbase.util.Pair;
  import org.apache.hadoop.metrics2.lib.DynamicMetricsRegistry;
  import org.apache.hadoop.metrics2.lib.MutableGaugeLong;
  import org.apache.hadoop.util.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * The Class ExecutorStatusChore for collect Executor status info periodically
   * and report to metrics system
   */
  @InterfaceAudience.Private
  public class ExecutorStatusChore extends ScheduledChore {
    private static final Logger LOG = LoggerFactory.getLogger(HealthCheckChore.class);
    public static final String WAKE_FREQ = "hbase.executors.status.collect.period";
    public static final int DEFAULT_WAKE_FREQ = 60000;
    private ExecutorService service;
    private DynamicMetricsRegistry metricsRegistry;
  
    public ExecutorStatusChore(int sleepTime, Stoppable stopper, ExecutorService service,
        MetricsRegionServerSource metrics) {
      super("ExecutorStatusChore", stopper, sleepTime);
      LOG.info("ExecutorStatusChore runs every {} ", StringUtils.formatTime(sleepTime));
      this.service = service;
      this.metricsRegistry = ((MetricsRegionServerSourceImpl) metrics).getMetricsRegistry();
    }
  
    @Override
    protected void chore() {
      try{
        // thread pool monitor
        Map<String, ExecutorStatus> statuses = service.getAllExecutorStatuses();
        for (Map.Entry<String, ExecutorStatus> statusEntry : statuses.entrySet()) {
          String name = statusEntry.getKey();
          // Executor's name is generate by ExecutorType#getExecutorName
          // include ExecutorType & Servername(split by '-'), here we only need the ExecutorType
          String poolName = name.split("-")[0];
          ExecutorStatus status = statusEntry.getValue();
          MutableGaugeLong queued = metricsRegistry.getGauge(poolName + "_queued", 0L);
          MutableGaugeLong running = metricsRegistry.getGauge(poolName + "_running", 0L);
          int queueSize = status.getQueuedEvents().size();
          int runningSize = status.getRunning().size();
          if (queueSize > 0) {
            LOG.warn("{}'s size info, queued: {}, running: {}", poolName, queueSize, runningSize);
          }
          queued.set(queueSize);
          running.set(runningSize);
        }
      } catch(Throwable e) {
        LOG.error(e.getMessage(), e);
      }
    }
  
    public Pair<Long, Long> getExecutorStatus(String poolName) {
      MutableGaugeLong running = metricsRegistry.getGauge(poolName + "_running", 0L);
      MutableGaugeLong queued = metricsRegistry.getGauge(poolName + "_queued", 0L);
      return new Pair<Long, Long>(running.value(), queued.value());
    }
  }