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.cassandra.metrics;
  
  import java.io.Serializable;
  import java.net.UnknownHostException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.codahale.metrics.Counter;
  import com.codahale.metrics.Gauge;
  import com.codahale.metrics.Histogram;
  import com.codahale.metrics.Meter;
  import com.github.benmanes.caffeine.cache.Caffeine;
  import com.github.benmanes.caffeine.cache.LoadingCache;
  import org.apache.cassandra.concurrent.ImmediateExecutor;
  import org.apache.cassandra.hints.HintsService;
  import org.apache.cassandra.locator.InetAddressAndPort;
  
  import static org.apache.cassandra.metrics.CassandraMetricsRegistry.Metrics;
  
  /**
   * Metrics for {@link org.apache.cassandra.hints.HintsService}.
   */
  public final class HintsServiceMetrics
  {
      public static final String TYPE_NAME = "HintsService";
  
      // Hint metrics are by address and hints that are for Accord need an address
      public static final InetAddressAndPort ACCORD_HINT_ENDPOINT;
  
      static
      {
          try
          {
              ACCORD_HINT_ENDPOINT = InetAddressAndPort.getByNameOverrideDefaults("0.0.0.0", 0);
          }
          catch (UnknownHostException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      private static final Logger logger = LoggerFactory.getLogger(HintsServiceMetrics.class);
  
      private static final MetricNameFactory factory = new DefaultNameFactory(TYPE_NAME);
  
      public static final Meter hintsSucceeded = Metrics.meter(factory.createMetricName("HintsSucceeded"));
      public static final Meter hintsFailed    = Metrics.meter(factory.createMetricName("HintsFailed"));
      public static final Meter hintsTimedOut  = Metrics.meter(factory.createMetricName("HintsTimedOut"));
      public static final Meter hintsRetryDifferentSystem  = Metrics.meter(factory.createMetricName("HintsRetryDifferentSystem"));
  
      public static final Gauge<Long> hintsFileSize = Metrics.gauge(factory.createMetricName("HintsFileSize"), new TotalHintsSizeGauge());
      // Corresponding to the hinted_handoff_throttle_in_kb configuration
      public static final Counter hintsThrottle = Metrics.counter(factory.createMetricName("HintsThrottle"));
  
      public static final Meter hintsApplySucceeded = Metrics.meter(factory.createMetricName("HintsApplySucceeded"));
      public static final Meter hintsApplyFailed = Metrics.meter(factory.createMetricName("HintsApplyFailed"));
  
      /** Histogram of all hint delivery delays */
      private static final Histogram globalDelayHistogram = Metrics.histogram(factory.createMetricName("Hint_delays"), false);
  
      /** Histograms per-endpoint of hint delivery delays, This is not a cache. */
      private static final LoadingCache<InetAddressAndPort, Histogram> delayByEndpoint = Caffeine.newBuilder()
                                                                                                 .executor(ImmediateExecutor.INSTANCE)
                                                                                                 .build(address -> Metrics.histogram(factory.createMetricName("Hint_delays-"+address.toString().replace(':', '.')), false));
  
      // because at the time of static hintsFileSize being initialized,
      // HintsService.instance is null / is not initialized yet so usage of method reference is not possible,
      // so this is the workaround.
      private static class TotalHintsSizeGauge implements Gauge<Long>, Serializable
      {
          @Override
          public Long getValue()
          {
              return HintsService.instance.getTotalHintsSize();
          }
      }
  
      public static void updateDelayMetrics(InetAddressAndPort endpoint, long delay)
      {
          if (delay <= 0)
          {
              logger.warn("Invalid negative latency in hint delivery delay: {}", delay);
              return;
          }
  
          globalDelayHistogram.update(delay);
          delayByEndpoint.get(endpoint).update(delay);
      }
  
      public static long getDelayCount(InetAddressAndPort endpoint)
      {
          return delayByEndpoint.get(endpoint).getCount();
      }
  }
  