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.gms;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Random;
  import java.util.Set;
  import java.util.UUID;
  import java.util.concurrent.ExecutionException;
  
  import com.google.common.collect.Sets;
  import org.junit.Test;
  
  import org.apache.cassandra.ServerTestUtils;
  import org.apache.cassandra.dht.Murmur3Partitioner;
  import org.apache.cassandra.locator.InetAddressAndPort;
  import org.apache.cassandra.net.ConnectionType;
  import org.apache.cassandra.net.Message;
  import org.apache.cassandra.net.MessageDelivery;
  import org.apache.cassandra.net.RequestCallback;
  import org.apache.cassandra.tcm.compatibility.GossipHelper;
  import org.apache.cassandra.utils.concurrent.Future;
  
  import static org.apache.cassandra.gms.ApplicationState.*;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  public class NewGossiperTest
  {
      static Set<InetAddressAndPort> fakePeers = new HashSet<>();
      static
      {
          for (int i = 1; i < 21; i++) // we require 10% of nodes to respond, so for two responses we need a cluster with 20 nodes
              fakePeers.add(InetAddressAndPort.getByNameUnchecked("127.0.0." + i));
      }
  
      @Test
      public void mergeTest() throws InterruptedException, ExecutionException
      {
          ServerTestUtils.prepareServerNoRegister();
  
          Random r = new Random(System.currentTimeMillis());
          for (int i = 0; i < 5000; i++)
          {
              NewGossiper.ShadowRoundHandler srh = new NewGossiper.ShadowRoundHandler(fakePeers, new NoOpMessageDelivery());
              Future<Map<InetAddressAndPort, EndpointState>> states = srh.doShadowRound();
              Map<InetAddressAndPort, EndpointState> firstResp = buildEpstates(fakePeers, r);
              srh.onAck(firstResp);
              Map<InetAddressAndPort, EndpointState> secondResp = buildEpstates(fakePeers, r);
              srh.onAck(secondResp);
              Map<InetAddressAndPort, EndpointState> result = states.get();
              verifyResult(result, firstResp, secondResp);
          }
      }
  
      private static void verifyResult(Map<InetAddressAndPort, EndpointState> result,
                                       Map<InetAddressAndPort, EndpointState> firstResp,
                                       Map<InetAddressAndPort, EndpointState> secondResp)
      {
          assertEquals(Sets.union(firstResp.keySet(), secondResp.keySet()), result.keySet());
          assertTrue(GossipHelper.isValidForClusterMetadata(result));
  
          for (InetAddressAndPort ep : Sets.union(firstResp.keySet(), secondResp.keySet()))
          {
              EndpointState first = firstResp.get(ep);
              EndpointState second = secondResp.get(ep);
              assertTrue(first != null || second != null);
              if (first == null)
                  assertEquals(second, result.get(ep));
              else if (second == null)
                  assertEquals(first, result.get(ep));
              else if (first.getHeartBeatState().getGeneration() > second.getHeartBeatState().getGeneration())
                  assertEquals(first, result.get(ep));
              else if (first.getHeartBeatState().getGeneration() < second.getHeartBeatState().getGeneration())
                  assertEquals(second, result.get(ep));
              else // equal generations
              {
                  if (first.isSupersededBy(second))
                      assertEquals(second, result.get(ep));
                  else if (second.isSupersededBy(first))
                      assertEquals(first, result.get(ep));
                  else
                      assertEquals(Gossiper.getMaxEndpointStateVersion(first), Gossiper.getMaxEndpointStateVersion(second));
              }
          }
      }
  
      private static Map<InetAddressAndPort, EndpointState> buildEpstates(Set<InetAddressAndPort> fakePeers, Random r)
      {
          Map<InetAddressAndPort, EndpointState> epstates = new HashMap<>();
  
          VersionedValue.VersionedValueFactory vvf = new VersionedValue.VersionedValueFactory(Murmur3Partitioner.instance, () -> r.nextInt(500));
          for (InetAddressAndPort endpoint : fakePeers)
          {
              if (r.nextDouble() < 0.001)
                  continue;
              EndpointState epstate = new EndpointState(new HeartBeatState(r.nextInt(50), r.nextInt(100)));
              epstate.addApplicationState(TOKENS, vvf.tokens(Collections.singleton(new Murmur3Partitioner.LongToken(r.nextInt(5000)))));
              epstate.addApplicationState(HOST_ID, vvf.hostId(UUID.randomUUID()));
              epstate.addApplicationState(DC, vvf.datacenter("dc" + r.nextInt(5)));
              epstate.addApplicationState(RACK, vvf.rack("rack" + r.nextInt(5)));
              epstate.addApplicationState(RELEASE_VERSION, vvf.releaseVersion("5.0."+r.nextInt()));
              epstates.put(endpoint, epstate);
          }
          return epstates;
      }
  
      private static class NoOpMessageDelivery implements MessageDelivery
      {
          public <REQ> void send(Message<REQ> message, InetAddressAndPort to) {}
          public <REQ, RSP> void sendWithCallback(Message<REQ> message, InetAddressAndPort to, RequestCallback<RSP> cb) {}
          public <REQ, RSP> void sendWithCallback(Message<REQ> message, InetAddressAndPort to, RequestCallback<RSP> cb, ConnectionType specifyConnection) {}
          public <REQ, RSP> Future<Message<RSP>> sendWithResult(Message<REQ> message, InetAddressAndPort to) {return null;}
          public <V> void respond(V response, Message<?> message) {}
      }
  
      @Test
      public void testIncompleteState()
      {
          Map<InetAddressAndPort, EndpointState> epstates = buildEpstates(Collections.singleton(fakePeers.iterator().next()), new Random());
          assertTrue(GossipHelper.isValidForClusterMetadata(epstates));
          Map<InetAddressAndPort, EndpointState> brokenEpstates = new HashMap<>();
          for (Map.Entry<InetAddressAndPort, EndpointState> entry : epstates.entrySet())
          {
              EndpointState epstate = new EndpointState(entry.getValue().getHeartBeatState());
              for (Map.Entry<ApplicationState, VersionedValue> vals : entry.getValue().states())
              {
                  if (vals.getKey() != TOKENS)
                      epstate.addApplicationState(vals.getKey(), vals.getValue());
              }
          }
          assertFalse(GossipHelper.isValidForClusterMetadata(brokenEpstates)); // does not contain TOKEN anymore
      }
  }
  