LeaderElection

["Trym R. Møller" <tr...@sigmat.dk>]

Hi

Messing with behaviour when Solr looses its ZooKeeper connection I'm 
trying to reproduce how a replica slice gets leader. I have made the 
below unit test in the LeaderElectionTest class which fails.
I don't know if this simulates how Solr uses the LeaderElection class 
but please comment on the scenario.

Thanks in advance.

Best regards Trym

   @Test
   public void testMemoryElection() throws Exception {
     LeaderElector first = new LeaderElector(zkClient);
     ZkNodeProps props = new ZkNodeProps(ZkStateReader.BASE_URL_PROP,
         "http://127.0.0.1/solr/", ZkStateReader.CORE_NAME_PROP, "1");
     ElectionContext firstContext = new 
ShardLeaderElectionContextBase(first,
         "slice1", "collection2", "dummynode1", props, zkStateReader);
     first.setup(firstContext);
     first.joinElection(firstContext);

     Thread.sleep(1000);
     assertEquals("original leader was not registered", 
"http://127.0.0.1/solr/1/", getLeaderUrl("collection2", "slice1"));

     SolrZkClient zkClient2 = new SolrZkClient(server.getZkAddress(), 
TIMEOUT);
     LeaderElector second = new LeaderElector(zkClient2);
     props = new ZkNodeProps(ZkStateReader.BASE_URL_PROP,
         "http://127.0.0.1/solr/", ZkStateReader.CORE_NAME_PROP, "2");
     ElectionContext context = new ShardLeaderElectionContextBase(second,
         "slice1", "collection2", "dummynode1", props, zkStateReader);
     second.setup(context);
     second.joinElection(context);
     Thread.sleep(1000);
     assertEquals("original leader should have stayed leader", 
"http://127.0.0.1/solr/1/", getLeaderUrl(zkClient2, "collection2", 
"slice1"));

     server.expire(zkClient.getSolrZooKeeper().getSessionId());

     assertEquals("new leader was not registered", 
"http://127.0.0.1/solr/2/", getLeaderUrl(zkClient2, "collection2", 
"slice1"));
   }