solr/core/src/test/org/apache/solr/cloud/LeaderElectionIntegrationTest.java

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 * 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
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.solr.cloud;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util.LuceneTestCase.Slow;
import org.apache.solr.SolrTestUtil;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.embedded.JettySolrRunner;
import org.apache.solr.client.solrj.request.CollectionAdminRequest;
import org.apache.solr.common.cloud.SolrZooKeeper;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.cloud.ZkStateReader;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Ignore;
import org.junit.Test;

@Slow
@LuceneTestCase.Nightly
@Ignore // MRM TODO:
public class LeaderElectionIntegrationTest extends SolrCloudTestCase {
  private final static int NUM_REPLICAS_OF_SHARD1 = 5;

  @BeforeClass
  public static void beforeLeaderElectionIntegrationTest() {
    System.setProperty("solrcloud.skip.autorecovery", "true");
  }

  @Override
  public void setUp() throws Exception {
    useFactory(null);
    super.setUp();
    configureCluster(6)
        .addConfig("conf", SolrTestUtil.configset("cloud-minimal"))
        .configure();
  }


  private void createCollection(String collection) throws IOException, SolrServerException {
    assertEquals(0, CollectionAdminRequest.createCollection(collection,
        "conf", 2, 1)
        .setMaxShardsPerNode(3).process(cluster.getSolrClient()).getStatus());
    for (int i = 1; i < NUM_REPLICAS_OF_SHARD1; i++) {
      assertTrue(
          CollectionAdminRequest.addReplicaToShard(collection, "s1").process(cluster.getSolrClient()).isSuccess()
      );
    }
  }

  @Test
  // 12-Jun-2018 @BadApple(bugUrl="https://issues.apache.org/jira/browse/SOLR-12028") // 04-May-2018
  // commented 4-Sep-2018 @LuceneTestCase.BadApple(bugUrl="https://issues.apache.org/jira/browse/SOLR-12028") // 2-Aug-2018
  public void testSimpleSliceLeaderElection() throws Exception {
    String collection = "collection1";
    createCollection(collection);
    cluster.waitForActiveCollection(collection, 10, TimeUnit.SECONDS, 2, 6);
    List<JettySolrRunner> stoppedRunners = new ArrayList<>();
    for (int i = 0; i < 4; i++) {
      // who is the leader?
      String leader = getLeader(collection);
      JettySolrRunner jetty = getRunner(leader);
      assertNotNull(jetty);
      assertTrue("s1".equals(jetty.getCoreContainer().getCores().iterator().next()
          .getCoreDescriptor().getCloudDescriptor().getShardId()));
      jetty.stop();
      stoppedRunners.add(jetty);
    }



    for (JettySolrRunner runner : stoppedRunners) {
      runner.start();
    }

    CollectionAdminRequest.deleteCollection(collection).process(cluster.getSolrClient());

    // testLeaderElectionAfterClientTimeout
    collection = "collection2";
    createCollection(collection);

    // TODO: work out the best timing here...
    System.setProperty("zkClientTimeout", Integer.toString(ZkTestServer.TICK_TIME * 2 + 100));
    // timeout the leader
    String leader = getLeader(collection);
    JettySolrRunner jetty = getRunner(leader);
    ZkController zkController = jetty.getCoreContainer().getZkController();

    ((SolrZooKeeper)zkController.getZkClient().getConnectionManager().getKeeper()).closeCnxn();
    cluster.getZkServer().expire(zkController.getZkClient().getConnectionManager().getKeeper().getSessionId());

    for (int i = 0; i < 60; i++) { // wait till leader is changed
      if (jetty != getRunner(getLeader(collection))) {
        break;
      }
      Thread.sleep(100);
    }

    // make sure we have waited long enough for the first leader to have come back
    Thread.sleep(ZkTestServer.TICK_TIME * 2 + 100);

    // kill everyone but the first leader that should have reconnected by now
    for (JettySolrRunner jetty2 : cluster.getJettySolrRunners()) {
      if (jetty != jetty2) {
        jetty2.stop();
      }
    }

    for (int i = 0; i < 320; i++) { // wait till leader is changed
      try {
        if (jetty == getRunner(getLeader(collection))) {
          break;
        }
        Thread.sleep(100);
      } catch (Exception e) {
        continue;
      }
    }

    assertEquals(jetty, getRunner(getLeader(collection)));
  }

  private JettySolrRunner getRunner(String nodeName) {
    for (JettySolrRunner jettySolrRunner : cluster.getJettySolrRunners()){
      if (!jettySolrRunner.isStopped() && nodeName.equals(jettySolrRunner.getNodeName())) return jettySolrRunner;
    }
    return null;
  }

  private String getLeader(String collection) throws InterruptedException, TimeoutException {

    ZkNodeProps props = cluster.getSolrClient().getZkStateReader().getLeaderRetry(collection, "s1", 30000);
    String leader = props.getStr(ZkStateReader.NODE_NAME_PROP);

    return leader;
  }

  @AfterClass
  public static void afterLeaderElectionIntegrationTest() throws InterruptedException {
    System.clearProperty("solrcloud.skip.autorecovery");
  }
}