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.Collection;
  import java.util.stream.Collectors;
  
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.Parameterized;
  
  import com.codahale.metrics.Counter;
  import com.codahale.metrics.Histogram;
  import com.codahale.metrics.Snapshot;
  import com.datastax.driver.core.QueryOptions;
  import org.apache.cassandra.cql3.CQLTester;
  import org.apache.cassandra.metrics.DecayingEstimatedHistogramReservoir.EstimatedHistogramReservoirSnapshot;
  import org.apache.cassandra.metrics.DecayingEstimatedHistogramReservoir.Range;
  import org.apache.cassandra.transport.ProtocolVersion;
  
  import static org.assertj.core.api.Assertions.assertThat;
  import static org.junit.Assert.assertEquals;
  
  /**
   * Ensures we properly account for metrics tracked in the native protocol
   */
  @RunWith(Parameterized.class)
  public class ClientRequestSizeMetricsTest extends CQLTester
  {
  
      @Parameterized.Parameter
      public ProtocolVersion version;
  
      @Parameterized.Parameters()
      public static Collection<Object[]> versions()
      {
          return ProtocolVersion.SUPPORTED.stream()
                                          .map(v -> new Object[]{ v })
                                          .collect(Collectors.toList());
      }
  
      @BeforeClass
      public static void setUp()
      {
          requireNetwork();
      }
  
      @Test
      public void testReadAndWriteMetricsAreRecordedDuringNativeRequests() throws Throwable
      {
          // It may happen that the schema refreshment is done in the middle of the test which can pollute the results
          // We explicitly disable scheme fetching to avoid that effect
          try
          {
              reinitializeNetwork(builder -> {}, builder -> builder.withQueryOptions(new QueryOptions().setMetadataEnabled(false)));
              sessionNet(version); // Ensure that the connection is open
  
              // We want to ignore all the messages sent by the driver upon connection as well as
              // the event sent upon schema updates
              clearMetrics();
  
              executeNet(version, "SELECT * from system.peers");
  
              long requestLength = ClientMessageSizeMetrics.bytesReceived.getCount();
              long responseLength = ClientMessageSizeMetrics.bytesSent.getCount();
  
              assertThat(requestLength).isGreaterThan(0);
              assertThat(responseLength).isGreaterThan(0);
  
              checkMetrics(1, requestLength, responseLength);
  
              // Let's fire the same request again and test that the changes are the same that previously
              executeNet(version, "SELECT * from system.peers");
  
              checkMetrics(2, requestLength, responseLength);
          }
          finally
          {
              reinitializeNetwork();
          }
      }
  
      private void checkMetrics(int numberOfRequests, long requestLength, long responseLength)
      {
          Snapshot snapshot;
          long expectedTotalBytesRead = numberOfRequests * requestLength;
          assertEquals(expectedTotalBytesRead, ClientMessageSizeMetrics.bytesReceived.getCount());
  
          long expectedTotalBytesWritten = numberOfRequests * responseLength;
          assertEquals(expectedTotalBytesWritten, ClientMessageSizeMetrics.bytesSent.getCount());
  
          // The request fit in one single frame so we know the new number of received frames
          assertEquals(numberOfRequests, ClientMessageSizeMetrics.bytesReceivedPerRequest.getCount());
  
          snapshot = ClientMessageSizeMetrics.bytesReceivedPerRequest.getSnapshot();
          assertMin(snapshot, requestLength);
          assertMax(snapshot, requestLength);
  
          // The response fit in one single frame so we know the new number of received frames
          assertEquals(numberOfRequests, ClientMessageSizeMetrics.bytesSentPerResponse.getCount());
  
          snapshot = ClientMessageSizeMetrics.bytesSentPerResponse.getSnapshot();
          assertMin(snapshot, responseLength);
          assertMax(snapshot, responseLength);
      }
  
      private void assertMin(Snapshot snapshot, long value)
      {
          Range range = ((EstimatedHistogramReservoirSnapshot) snapshot).getBucketingRangeForValue(value);
          assertEquals(snapshot.getMin(), range.min);
      }
  
      private void assertMax(Snapshot snapshot, long value)
      {
          Range range = ((EstimatedHistogramReservoirSnapshot) snapshot).getBucketingRangeForValue(value);
          assertEquals(snapshot.getMax(), range.max);
      }
  
      private void clearMetrics()
      {
          clearCounter(ClientMessageSizeMetrics.bytesReceived);
          clearCounter(ClientMessageSizeMetrics.bytesSent);
          clearHistogram(ClientMessageSizeMetrics.bytesReceivedPerRequest);
          clearHistogram(ClientMessageSizeMetrics.bytesSentPerResponse);
      }
  
      private void clearCounter(Counter counter)
      {
          counter.dec(counter.getCount());
      }
  
      private void clearHistogram(Histogram histogram)
      {
          ((ClearableHistogram) histogram).clear();
      }
  }
  