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.util.Map.Entry;
  
  import com.codahale.metrics.Counter;
  import com.github.benmanes.caffeine.cache.Caffeine;
  import com.github.benmanes.caffeine.cache.LoadingCache;
  
  import org.apache.cassandra.concurrent.ImmediateExecutor;
  import org.apache.cassandra.db.SystemKeyspace;
  import org.apache.cassandra.locator.InetAddressAndPort;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static org.apache.cassandra.metrics.CassandraMetricsRegistry.Metrics;
  import static org.apache.cassandra.utils.TimeUUID.Generator.nextTimeUUID;
  
  /**
   * Metrics for {@link org.apache.cassandra.hints.HintsService}.
   */
  public class HintedHandoffMetrics
  {
      public static final String TYPE_NAME = "HintsService";
      private static final Logger logger = LoggerFactory.getLogger(HintedHandoffMetrics.class);
  
      private static final MetricNameFactory factory = new DefaultNameFactory(TYPE_NAME);
  
      /** Total number of hints which are not stored, This is not a cache. */
      private final LoadingCache<InetAddressAndPort, DifferencingCounter> notStored = Caffeine.newBuilder()
                                                                                              .executor(ImmediateExecutor.INSTANCE)
                                                                                              .build(DifferencingCounter::new);
  
      /** Total number of hints that have been created, This is not a cache. */
      private final LoadingCache<InetAddressAndPort, Counter> createdHintCounts = Caffeine.newBuilder()
                                                                                          .executor(ImmediateExecutor.INSTANCE)
                                                                                          .build(address -> Metrics.counter(factory.createMetricName("Hints_created-" + address.toString().replace(':', '.'))));
  
      public void incrCreatedHints(InetAddressAndPort address)
      {
          createdHintCounts.get(address).inc();
      }
  
      public void incrPastWindow(InetAddressAndPort address)
      {
          notStored.get(address).mark();
      }
  
      public void log()
      {
          for (Entry<InetAddressAndPort, DifferencingCounter> entry : notStored.asMap().entrySet())
          {
              long difference = entry.getValue().difference();
              if (difference == 0)
                  continue;
              logger.warn("{} has {} dropped hints, because node is down past configured hint window.", entry.getKey(), difference);
              SystemKeyspace.updateHintsDropped(entry.getKey(), nextTimeUUID(), (int) difference);
          }
      }
  
      public static class DifferencingCounter
      {
          private final Counter meter;
          private long reported = 0;
  
          public DifferencingCounter(InetAddressAndPort address)
          {
              //This changes the name of the metric, people can update their monitoring when upgrading?
              this.meter = Metrics.counter(factory.createMetricName("Hints_not_stored-" + address.toString().replace(':', '.')));
          }
  
          public long difference()
          {
              long current = meter.getCount();
              long difference = current - reported;
              this.reported = current;
              return difference;
          }
  
          public long count()
          {
              return meter.getCount();
          }
  
          public void mark()
          {
              meter.inc();
          }
      }
  }
  