public static bool AmILeader(Server server)
{
try
{
bool result = helper.RetryOperation(() =>
{
IZooKeeper zookeeper = _zookeeper;
string shardLeaderPath = ZkPath.LeaderPath(ZkPath.CollectionName, server.ShardName);
Stat stat = zookeeper.Exists(shardLeaderPath, null);
if (stat == null)
{
throw new NotProcessLeaderElectionException(shardLeaderPath);
}
Server dataServer = getDataSever(shardLeaderPath);
if (dataServer == server)
{
return(true);
}
else
{
return(false);
}
});
return(result);
}
catch (KeeperException.SessionExpiredException ex)
{
helper.Dispose();
helper = new LeaderHelper(_zookeeper);
throw ex;
}
}
/**
* Kill the given ZK session
*
* @param client the client to kill
* @param connectString server connection string
* @param maxMs max time ms to wait for kill
* @throws Exception errors
*/
public static void kill(IZooKeeper client, String connectString, int maxMs)
{
System.Diagnostics.Debug.WriteLine("Kill Start");
long startTicks = (long)TimeSpan.FromTicks(System.DateTime.Now.Ticks).TotalMilliseconds;
var sessionLostLatch = new AutoResetEvent(false);
IWatcher sessionLostWatch = new CuratorWatcher((e) => { if (e.State == KeeperState.Expired)
{
sessionLostLatch.Set();
}
});
client.Exists("/___CURATOR_KILL_SESSION___" + System.DateTime.Now.Ticks, sessionLostWatch);
var connectionLatch = new AutoResetEvent(false);
var connectionWatcher = new CuratorWatcher((e) => {
if (e.State == KeeperState.SyncConnected)
{
connectionLatch.Set();
}
});
IZooKeeper zk = new ZooKeeper(connectString, TimeSpan.FromMilliseconds(maxMs), connectionWatcher, client.SessionId, client.SesionPassword);
try
{
if (!connectionLatch.WaitOne(maxMs))
{
throw new Exception("KillSession could not establish duplicate session");
}
try
{
zk.Dispose();
}
finally
{
zk = null;
}
while (client.State.IsAlive() && !sessionLostLatch.WaitOne(100))
{
long elapsed = (long)TimeSpan.FromTicks(System.DateTime.Now.Ticks).TotalMilliseconds - startTicks;
if (elapsed > maxMs)
{
throw new Exception("KillSession timed out waiting for session to expire");
}
}
}
finally
{
if (zk != null)
{
zk.Dispose();
}
}
System.Diagnostics.Debug.WriteLine("Kill End");
}
public void Process(WatchedEvent ev)
{
var path = ev.Path;
var value = string.Empty;
//debug
switch (ev.Type)
{
case EventType.None:
break;
case EventType.NodeCreated:
value = Zookeeper.GetData(path, this, null).GetString();
zkCache.SetValue(path, value);
Zookeeper.Exists(path, this);
LOG.Debug(" >>NodeCreated:" + value);
System.Console.WriteLine(" >>NodeCreated:" + value);
break;
case EventType.NodeDeleted:
Zookeeper.Exists(path, this);
LOG.Debug(" >>NodeDeleted:" + value);
System.Console.WriteLine(" >>NodeDeleted:" + value);
break;
case EventType.NodeDataChanged:
value = Zookeeper.GetData(path, this, null).GetString();
zkCache.SetValue(path, value);
Zookeeper.Exists(path, this);
LOG.Debug(" >>NodeDataChanged:" + value);
System.Console.WriteLine(" >>NodeDataChanged:" + value);
break;
case EventType.NodeChildrenChanged:
break;
default:
break;
}
}
/**
* Kill the given ZK session
*
* @param client the client to kill
* @param connectString server connection string
* @param maxMs max time ms to wait for kill
* @throws Exception errors
*/
public static void kill(IZooKeeper client, String connectString, int maxMs)
{
System.Diagnostics.Debug.WriteLine ("Kill Start");
long startTicks = (long)TimeSpan.FromTicks(System.DateTime.Now.Ticks).TotalMilliseconds;
var sessionLostLatch = new AutoResetEvent(false);
IWatcher sessionLostWatch = new CuratorWatcher((e)=> { if(e.State == KeeperState.Expired) sessionLostLatch.Set();});
client.Exists("/___CURATOR_KILL_SESSION___" + System.DateTime.Now.Ticks, sessionLostWatch);
var connectionLatch = new AutoResetEvent(false);
var connectionWatcher = new CuratorWatcher((e)=> {
if(e.State == KeeperState.SyncConnected){
connectionLatch.Set();
}
});
IZooKeeper zk = new ZooKeeper(connectString, TimeSpan.FromMilliseconds(maxMs), connectionWatcher, client.SessionId, client.SesionPassword);
try
{
if ( !connectionLatch.WaitOne(maxMs) )
{
throw new Exception("KillSession could not establish duplicate session");
}
try
{
zk.Dispose();
}
finally
{
zk = null;
}
while ( client.State.IsAlive() && !sessionLostLatch.WaitOne(100) )
{
long elapsed = (long)TimeSpan.FromTicks(System.DateTime.Now.Ticks).TotalMilliseconds - startTicks;
if ( elapsed > maxMs )
{
throw new Exception("KillSession timed out waiting for session to expire");
}
}
}
finally
{
if ( zk != null )
{
zk.Dispose();
}
}
System.Diagnostics.Debug.WriteLine ("Kill End");
}
public static Server ShardLeader(string shardName)
{
IZooKeeper zookeeper = _zookeeper;
string shardLeaderPath = ZkPath.LeaderPath(ZkPath.CollectionName, shardName);
Stat stat = zookeeper.Exists(shardLeaderPath, null);
if (stat == null)
{
return(null);
}
Server dataServer = getDataSever(shardLeaderPath);
return(dataServer);
}
public void TestExpiredSession()
{
var timing = new Timing();
var latch = new AutoResetEvent(false);
var watcher = new CuratorWatcher((e) => {
if (e.State == KeeperState.Expired)
{
latch.Set();
}
});
using (var client = new CuratorZookeeperClient(server.GetConnectionString(), timing.session(), timing.connection(), watcher, new RetryOneTime(TimeSpan.FromMilliseconds(2))))
{
client.Start();
bool firstTime = true;
RetryLoop.CallWithRetry <bool>(client, () =>
{
if (firstTime)
{
try
{
var stat = client.GetZooKeeper().Exists("/foo", false);
if (stat == null)
{
client.GetZooKeeper().Create("/foo", new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.Persistent);
}
}
catch (KeeperException.NodeExistsException ignore)
{
}
KillSession.kill(client.GetZooKeeper(), server.GetConnectionString());
Assert.IsFalse(timing.awaitLatch(latch));
}
IZooKeeper zooKeeper = client.GetZooKeeper();
client.BlockUntilConnectedOrTimedOut();
Assert.IsNotNull(zooKeeper.Exists("/foo", false));
return(true);
});
}
}
/// <summary>
/// Attempt to delete the lock node so that sequence numbers get reset.
/// </summary>
public void Clean()
{
try
{
// Don't blindly do delete or things get noisy in the INFO logs on the
// server.
var stat = _client.Exists(_basePath, false);
if (null != stat && stat.NumChildren < 1)
{
_client.Delete(_basePath, -1);
}
}
catch (KeeperException.BadVersionException)
{
// Intentially ignore this - another thread/process got the lock
}
catch (KeeperException.NotEmptyException)
{
// Intentially ignore this - other threads/processes are waiting
}
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @param makeLastNode if true, all nodes are created. If false, only the parent nodes are created
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException
* Zookeeper errors
*/
public static void Mkdirs(IZooKeeper zookeeper, String path, bool makeLastNode)
{
PathUtils.ValidatePath(path);
var pos = 1; // skip first slash, root is guaranteed to exist
do
{
pos = path.IndexOf(PathUtils.PathSeparatorChar, pos + 1);
if (pos == -1)
{
if (makeLastNode)
{
pos = path.Length;
}
else
{
break;
}
}
var subPath = path.Substring(0, pos);
if (zookeeper.Exists(subPath, false) == null)
{
try
{
zookeeper.Create(subPath, new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.Persistent);
}
catch (KeeperException.NodeExistsException e)
{
// ignore... someone else has created it since we checked
}
}
}while (pos < path.Length);
}
/**
* Make sure all the nodes in the path are created. NOTE: Unlike File.mkdirs(), Zookeeper doesn't distinguish
* between directories and files. So, every node in the path is created. The data for each node is an empty blob
*
* @param zookeeper the client
* @param path path to ensure
* @param makeLastNode if true, all nodes are created. If false, only the parent nodes are created
* @throws InterruptedException thread interruption
* @throws org.apache.zookeeper.KeeperException
* Zookeeper errors
*/
public static void Mkdirs(IZooKeeper zookeeper, String path, bool makeLastNode)
{
PathUtils.ValidatePath(path);
var pos = 1; // skip first slash, root is guaranteed to exist
do
{
pos = path.IndexOf(PathUtils.PathSeparatorChar, pos + 1);
if (pos == -1)
{
if (makeLastNode)
{
pos = path.Length;
}
else
{
break;
}
}
var subPath = path.Substring(0, pos);
if (zookeeper.Exists(subPath, false) == null)
{
try
{
zookeeper.Create(subPath, new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.Persistent);
}
catch (KeeperException.NodeExistsException e)
{
// ignore... someone else has created it since we checked
}
}
}
while (pos < path.Length);
}
