/**
* expire zk session asynchronously
*
* @param zkClient
* @throws Exception
*/
public static void asyncExpireSession(final ZkClient zkClient) throws Exception {
ZkConnection connection = ((ZkConnection) zkClient.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
LOG.info("Before expiry. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
Watcher watcher =
new Watcher() {
@Override
public void process(WatchedEvent event) {
LOG.info("Process watchEvent: " + event);
}
};
final ZooKeeper dupZookeeper =
new ZooKeeper(
connection.getServers(),
curZookeeper.getSessionTimeout(),
watcher,
curZookeeper.getSessionId(),
curZookeeper.getSessionPasswd());
// wait until connected, then close
while (dupZookeeper.getState() != States.CONNECTED) {
Thread.sleep(10);
}
dupZookeeper.close();
connection = (ZkConnection) zkClient.getConnection();
curZookeeper = connection.getZookeeper();
// System.err.println("zk: " + oldZookeeper);
LOG.info("After expiry. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
}
public static Map<String, List<String>> getZkWatch(ZkClient client) throws Exception {
Map<String, List<String>> lists = new HashMap<String, List<String>>();
ZkConnection connection = ((ZkConnection) client.getConnection());
ZooKeeper zk = connection.getZookeeper();
java.lang.reflect.Field field = getField(zk.getClass(), "watchManager");
field.setAccessible(true);
Object watchManager = field.get(zk);
java.lang.reflect.Field field2 = getField(watchManager.getClass(), "dataWatches");
field2.setAccessible(true);
HashMap<String, Set<Watcher>> dataWatches =
(HashMap<String, Set<Watcher>>) field2.get(watchManager);
field2 = getField(watchManager.getClass(), "existWatches");
field2.setAccessible(true);
HashMap<String, Set<Watcher>> existWatches =
(HashMap<String, Set<Watcher>>) field2.get(watchManager);
field2 = getField(watchManager.getClass(), "childWatches");
field2.setAccessible(true);
HashMap<String, Set<Watcher>> childWatches =
(HashMap<String, Set<Watcher>>) field2.get(watchManager);
lists.put("dataWatches", new ArrayList<String>(dataWatches.keySet()));
lists.put("existWatches", new ArrayList<String>(existWatches.keySet()));
lists.put("childWatches", new ArrayList<String>(childWatches.keySet()));
return lists;
}
public static void disconnectSession(final ZkClient zkClient) throws Exception {
IZkStateListener listener =
new IZkStateListener() {
@Override
public void handleStateChanged(KeeperState state) throws Exception {
// System.err.println("disconnectSession handleStateChanged. state: " + state);
}
@Override
public void handleNewSession() throws Exception {
// make sure zkclient is connected again
zkClient.waitUntilConnected();
ZkConnection connection = ((ZkConnection) zkClient.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
LOG.info(
"handleNewSession. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
}
};
zkClient.subscribeStateChanges(listener);
ZkConnection connection = ((ZkConnection) zkClient.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
LOG.info("Before expiry. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
Watcher watcher =
new Watcher() {
@Override
public void process(WatchedEvent event) {
LOG.info("Process watchEvent: " + event);
}
};
final ZooKeeper dupZookeeper =
new ZooKeeper(
connection.getServers(),
curZookeeper.getSessionTimeout(),
watcher,
curZookeeper.getSessionId(),
curZookeeper.getSessionPasswd());
// wait until connected, then close
while (dupZookeeper.getState() != States.CONNECTED) {
Thread.sleep(10);
}
dupZookeeper.close();
connection = (ZkConnection) zkClient.getConnection();
curZookeeper = connection.getZookeeper();
zkClient.unsubscribeStateChanges(listener);
// System.err.println("zk: " + oldZookeeper);
LOG.info("After expiry. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
}
@Override
public boolean isConnected() {
if (_zkclient == null) {
return false;
}
ZkConnection zkconnection = (ZkConnection) _zkclient.getConnection();
if (zkconnection != null) {
States state = zkconnection.getZookeeperState();
return state == States.CONNECTED;
}
return false;
}
@Override
public void handleStateChanged(KeeperState state) throws Exception {
switch (state) {
case SyncConnected:
ZkConnection zkConnection = (ZkConnection) _zkclient.getConnection();
LOG.info("KeeperState: " + state + ", zookeeper:" + zkConnection.getZookeeper());
break;
case Disconnected:
LOG.info(
"KeeperState:"
+ state
+ ", disconnectedSessionId: "
+ _sessionId
+ ", instance: "
+ _instanceName
+ ", type: "
+ _instanceType);
/**
* Track the time stamp that the disconnected happens, then check history and see if we
* should disconnect the helix-manager
*/
_disconnectTimeHistory.add(System.currentTimeMillis());
if (isFlapping()) {
LOG.error(
"instanceName: "
+ _instanceName
+ " is flapping. diconnect it. "
+ " maxDisconnectThreshold: "
+ _maxDisconnectThreshold
+ " disconnects in "
+ _flappingTimeWindowMs
+ "ms.");
disconnect();
}
break;
case Expired:
LOG.info(
"KeeperState:"
+ state
+ ", expiredSessionId: "
+ _sessionId
+ ", instance: "
+ _instanceName
+ ", type: "
+ _instanceType);
break;
default:
break;
}
}
/**
* wait until we get a non-zero session-id. note that we might lose zkconnection right after we
* read session-id. but it's ok to get stale session-id and we will have another
* handle-new-session callback to correct this.
*/
void waitUntilConnected() {
boolean isConnected;
do {
isConnected =
_zkclient.waitUntilConnected(ZkClient.DEFAULT_CONNECTION_TIMEOUT, TimeUnit.MILLISECONDS);
if (!isConnected) {
LOG.error(
"fail to connect zkserver: "
+ _zkAddress
+ " in "
+ ZkClient.DEFAULT_CONNECTION_TIMEOUT
+ "ms. expiredSessionId: "
+ _sessionId
+ ", clusterName: "
+ _clusterName);
continue;
}
ZkConnection zkConnection = ((ZkConnection) _zkclient.getConnection());
_sessionId = Long.toHexString(zkConnection.getZookeeper().getSessionId());
/**
* at the time we read session-id, zkconnection might be lost again wait until we get a
* non-zero session-id
*/
} while ("0".equals(_sessionId));
LOG.info(
"Handling new session, session id: "
+ _sessionId
+ ", instance: "
+ _instanceName
+ ", instanceTye: "
+ _instanceType
+ ", cluster: "
+ _clusterName
+ ", zkconnection: "
+ ((ZkConnection) _zkclient.getConnection()).getZookeeper());
}
/**
* Expire current zk session and wait for {@link IZkStateListener#handleNewSession()} invoked
*
* @param zkClient
* @throws Exception
*/
public static void expireSession(final ZkClient zkClient) throws Exception {
final CountDownLatch waitNewSession = new CountDownLatch(1);
IZkStateListener listener =
new IZkStateListener() {
@Override
public void handleStateChanged(KeeperState state) throws Exception {
LOG.info("IZkStateListener#handleStateChanged, state: " + state);
}
@Override
public void handleNewSession() throws Exception {
// make sure zkclient is connected again
zkClient.waitUntilConnected();
ZkConnection connection = ((ZkConnection) zkClient.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
LOG.info(
"handleNewSession. sessionId: " + Long.toHexString(curZookeeper.getSessionId()));
waitNewSession.countDown();
}
};
zkClient.subscribeStateChanges(listener);
ZkConnection connection = ((ZkConnection) zkClient.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
String oldSessionId = Long.toHexString(curZookeeper.getSessionId());
LOG.info("Before session expiry. sessionId: " + oldSessionId + ", zk: " + curZookeeper);
Watcher watcher =
new Watcher() {
@Override
public void process(WatchedEvent event) {
LOG.info("Watcher#process, event: " + event);
}
};
final ZooKeeper dupZookeeper =
new ZooKeeper(
connection.getServers(),
curZookeeper.getSessionTimeout(),
watcher,
curZookeeper.getSessionId(),
curZookeeper.getSessionPasswd());
// wait until connected, then close
while (dupZookeeper.getState() != States.CONNECTED) {
Thread.sleep(10);
}
Assert.assertEquals(
dupZookeeper.getState(),
States.CONNECTED,
"Fail to connect to zk using current session info");
dupZookeeper.close();
// make sure session expiry really happens
waitNewSession.await();
zkClient.unsubscribeStateChanges(listener);
connection = (ZkConnection) zkClient.getConnection();
curZookeeper = connection.getZookeeper();
String newSessionId = Long.toHexString(curZookeeper.getSessionId());
LOG.info("After session expiry. sessionId: " + newSessionId + ", zk: " + curZookeeper);
Assert.assertNotSame(
newSessionId, oldSessionId, "Fail to expire current session, zk: " + curZookeeper);
}
/**
* Get zk connection session id
*
* @param client
* @return
*/
public static String getSessionId(ZkClient client) {
ZkConnection connection = ((ZkConnection) client.getConnection());
ZooKeeper curZookeeper = connection.getZookeeper();
return Long.toHexString(curZookeeper.getSessionId());
}