/**
* Add this instance to the leadership election and attempt to acquire leadership.
*
* @throws Exception errors
*/
public void start() throws Exception {
Preconditions.checkState(
state.compareAndSet(State.LATENT, State.STARTED), "Cannot be started more than once");
client.getConnectionStateListenable().addListener(listener);
reset();
}
/**
* Add this instance to the leadership election and attempt to acquire leadership.
*
* @throws Exception errors
*/
public void start() throws Exception {
Preconditions.checkState(state.compareAndSet(State.LATENT, State.STARTED), "Already started");
client.getConnectionStateListenable().addListener(listener);
client.newNamespaceAwareEnsurePath(latchPath).ensure(client.getZookeeperClient());
internalStart();
}
/**
* The shared value must be started before it can be used. Call {@link #close()} when you are
* finished with the shared value
*
* @throws Exception ZK errors, interruptions, etc.
*/
public void start() throws Exception {
Preconditions.checkState(state.compareAndSet(State.LATENT, State.STARTED), "already started");
client.getConnectionStateListenable().addListener(connectionStateListener);
try {
client.create().creatingParentsIfNeeded().forPath(path, seedValue);
} catch (KeeperException.NodeExistsException ignore) {
// ignore
}
readValue();
}
/**
* Remove this instance from the leadership election. If this instance is the leader, leadership
* is released. IMPORTANT: the only way to release leadership is by calling close(). All
* LeaderLatch instances must eventually be closed.
*
* @throws IOException errors
*/
@Override
public void close() throws IOException {
Preconditions.checkState(state.compareAndSet(State.STARTED, State.CLOSED), "Not started");
try {
client.delete().guaranteed().inBackground().forPath(ourPath);
} catch (Exception e) {
throw new IOException(e);
} finally {
client.getConnectionStateListenable().removeListener(listener);
setLeadership(false);
}
}
/**
* Remove this instance from the leadership election. If this instance is the leader, leadership
* is released. IMPORTANT: the only way to release leadership is by calling close(). All
* LeaderLatch instances must eventually be closed.
*
* @throws IOException errors
*/
@Override
public void close() throws IOException {
Preconditions.checkState(
state.compareAndSet(State.STARTED, State.CLOSED), "Already closed or has not been started");
try {
setNode(null);
} catch (Exception e) {
throw new IOException(e);
} finally {
client.getConnectionStateListenable().removeListener(listener);
setLeadership(false);
}
}
@Override
public void close() throws IOException {
client.getConnectionStateListenable().removeListener(connectionStateListener);
state.set(State.CLOSED);
listeners.clear();
}
private void buildZKClient(final String zkFullPath) {
final String[] zkFullPathItems = zkFullPath.split(ZK_FULL_PATH_DELIMITER);
zkHost_ = zkFullPathItems[1];
zkNamespace_ =
zkFullPathItems[2].substring(
0, zkFullPathItems[2].lastIndexOf(ZK_FULL_PATH_NAMESPACE_SEPERATOR));
zkNodePath_ =
zkFullPathItems[2].substring(
zkFullPathItems[2].lastIndexOf(ZK_FULL_PATH_NAMESPACE_SEPERATOR));
if (zkClient_ == null) {
try {
zkClient_ =
CuratorFrameworkFactory.builder()
.connectString(zkHost_)
.namespace(zkNamespace_)
.retryPolicy(new ExponentialBackoffRetry(1000, 60))
.connectionTimeoutMs(2 * 3600 * 1000)
.build();
zkClient_
.getConnectionStateListenable()
.addListener(
new ConnectionStateListener() {
@Override
public void stateChanged(CuratorFramework client, ConnectionState newState) {
// TODO Auto-generated method stub
if (newState == ConnectionState.LOST) {
try {
synchronized (this) {
while (!client.getZookeeperClient().blockUntilConnectedOrTimedOut()) {
if (logger_ != null) {
if (logger_.isInfoEnabled()) logger_.info("waitting reconnected...");
}
wait(1000);
}
}
if (logger_ != null) {
if (logger_.isInfoEnabled()) logger_.info("to zookeeper reconnected.");
}
doNodesDiscovery();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
if (logger_ != null) {
if (logger_.isInfoEnabled())
logger_.info(
String.format(
"To re connect to zookeeper to generate an error, cause:%s",
e));
}
}
}
}
});
zkClient_.start();
} catch (Throwable t) {
zkClient_.close();
throw new IllegalStateException("building zookeeper client failed.");
}
}
}
