org.apache.curator

Class CuratorZookeeperClient

java.lang.Object

org.apache.curator.CuratorZookeeperClient

All Implemented Interfaces:

Closeable, AutoCloseable

public class CuratorZookeeperClient
extends Object
implements Closeable

A wrapper around Zookeeper that takes care of some low-level housekeeping

Constructor Summary

Constructors

Constructor and Description
CuratorZookeeperClient(EnsembleProvider ensembleProvider, int sessionTimeoutMs, int connectionTimeoutMs, org.apache.zookeeper.Watcher watcher, RetryPolicy retryPolicy)
CuratorZookeeperClient(String connectString, int sessionTimeoutMs, int connectionTimeoutMs, org.apache.zookeeper.Watcher watcher, RetryPolicy retryPolicy)
CuratorZookeeperClient(ZookeeperFactory zookeeperFactory, EnsembleProvider ensembleProvider, int sessionTimeoutMs, int connectionTimeoutMs, org.apache.zookeeper.Watcher watcher, RetryPolicy retryPolicy, boolean canBeReadOnly)

Method Summary

Modifier and Type	Method and Description
boolean	blockUntilConnectedOrTimedOut() This method blocks until the connection to ZK succeeds.
void	close() Close the client
int	getConnectionTimeoutMs() Return the configured connection timeout
String	getCurrentConnectionString() Returns the current known connection string - not guaranteed to be correct value at any point in the future.
long	getInstanceIndex() Every time a new ZooKeeper instance is allocated, the "instance index" is incremented.
RetryPolicy	getRetryPolicy() Return the current retry policy
TracerDriver	getTracerDriver() Return the current tracing driver
org.apache.zookeeper.ZooKeeper	getZooKeeper() Return the managed ZK instance.
boolean	isConnected() Returns true if the client is current connected
RetryLoop	newRetryLoop() Return a new retry loop.
SessionFailRetryLoop	newSessionFailRetryLoop(SessionFailRetryLoop.Mode mode) Return a new "session fail" retry loop.
void	setRetryPolicy(RetryPolicy policy) Change the retry policy
void	setTracerDriver(TracerDriver tracer) Change the tracing driver
void	start() Must be called after construction
OperationTrace	startAdvancedTracer(String name) Start a new advanced tracer with more metrics being recorded
TimeTrace	startTracer(String name) Start a new tracer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CuratorZookeeperClient

public CuratorZookeeperClient(String connectString,
                              int sessionTimeoutMs,
                              int connectionTimeoutMs,
                              org.apache.zookeeper.Watcher watcher,
                              RetryPolicy retryPolicy)

Parameters:

connectString - list of servers to connect to

sessionTimeoutMs - session timeout

connectionTimeoutMs - connection timeout

watcher - default watcher or null

retryPolicy - the retry policy to use

CuratorZookeeperClient

public CuratorZookeeperClient(EnsembleProvider ensembleProvider,
                              int sessionTimeoutMs,
                              int connectionTimeoutMs,
                              org.apache.zookeeper.Watcher watcher,
                              RetryPolicy retryPolicy)

Parameters:

ensembleProvider - the ensemble provider

sessionTimeoutMs - session timeout

connectionTimeoutMs - connection timeout

watcher - default watcher or null

retryPolicy - the retry policy to use

CuratorZookeeperClient

public CuratorZookeeperClient(ZookeeperFactory zookeeperFactory,
                              EnsembleProvider ensembleProvider,
                              int sessionTimeoutMs,
                              int connectionTimeoutMs,
                              org.apache.zookeeper.Watcher watcher,
                              RetryPolicy retryPolicy,
                              boolean canBeReadOnly)

Parameters:

zookeeperFactory - factory for creating ZooKeeper instances

ensembleProvider - the ensemble provider

sessionTimeoutMs - session timeout

connectionTimeoutMs - connection timeout

watcher - default watcher or null

retryPolicy - the retry policy to use

canBeReadOnly - if true, allow ZooKeeper client to enter read only mode in case of a network partition. See ZooKeeper.ZooKeeper(String, int, Watcher, long, byte[], boolean) for details

Method Detail

getZooKeeper

public org.apache.zookeeper.ZooKeeper getZooKeeper()
                                            throws Exception

Return the managed ZK instance.

Returns:

client the client

Throws:

Exception - if the connection timeout has elapsed or an exception occurs in a background process

newRetryLoop

public RetryLoop newRetryLoop()

Return a new retry loop. All operations should be performed in a retry loop

Returns:

new retry loop

newSessionFailRetryLoop

public SessionFailRetryLoop newSessionFailRetryLoop(SessionFailRetryLoop.Mode mode)

Return a new "session fail" retry loop. See SessionFailRetryLoop for details on when to use it.

Parameters:

mode - failure mode

Returns:

new retry loop

isConnected

public boolean isConnected()

Returns true if the client is current connected

Returns:

true/false

blockUntilConnectedOrTimedOut

public boolean blockUntilConnectedOrTimedOut()
                                      throws InterruptedException

This method blocks until the connection to ZK succeeds. Use with caution. The block will timeout after the connection timeout (as passed to the constructor) has elapsed

Returns:

true if the connection succeeded, false if not

Throws:

InterruptedException - interrupted while waiting

start

public void start()
           throws Exception

Must be called after construction

Throws:

IOException - errors

Exception

close

public void close()

Close the client

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

setRetryPolicy

public void setRetryPolicy(RetryPolicy policy)

Change the retry policy

Parameters:

policy - new policy

getRetryPolicy

public RetryPolicy getRetryPolicy()

Return the current retry policy

Returns:

policy

startTracer

public TimeTrace startTracer(String name)

Start a new tracer

Parameters:

name - name of the event

Returns:

the new tracer (TimeTrace.commit() must be called)

startAdvancedTracer

public OperationTrace startAdvancedTracer(String name)

Start a new advanced tracer with more metrics being recorded

Parameters:

name - name of the event

Returns:

the new tracer (OperationTrace.commit() must be called)

getTracerDriver

public TracerDriver getTracerDriver()

Return the current tracing driver

Returns:

tracing driver

setTracerDriver

public void setTracerDriver(TracerDriver tracer)

Change the tracing driver

Parameters:

tracer - new tracing driver

getCurrentConnectionString

public String getCurrentConnectionString()

Returns the current known connection string - not guaranteed to be correct value at any point in the future.

Returns:

connection string

getConnectionTimeoutMs

public int getConnectionTimeoutMs()

Return the configured connection timeout

Returns:

timeout

getInstanceIndex

public long getInstanceIndex()

Every time a new ZooKeeper instance is allocated, the "instance index" is incremented.

Returns:

the current instance index