com.bigdata.zookeeper
Class ZooHelper

java.lang.Object
  com.bigdata.zookeeper.ZooHelper

public class ZooHelper
extends Object

Utility class for issuing the four letter commands to a zookeeper service.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

protected static org.apache.log4j.Logger

log

Constructor Summary

ZooHelper()

Method Summary

static void	destroyZNodes(org.apache.zookeeper.ZooKeeper zookeeper, String zpath, int depth) Destroys all znodes under the specified zpath and then the znode at the specified zpath.
static String	dump(InetAddress addr, int clientPort) Sends a "dump" command and return the result.
static boolean	isRunning(InetAddress addr, int clientPort) Return true if zookeeper is running on the specified host at the client port.
static void	kill(int clientPort) Kills a local zookeeper instance responding at the specified client port.
static void	main(String[] args) Send four letter commands to zookeeper.
static void	ruok(InetAddress addr, int clientPort) Inquires whether a zookeeper instance is running in a non-error state and returns iff the service reports "imok".
static String	stat(InetAddress addr, int clientPort) Sends a "stat" command and return the result.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.log4j.Logger log

Constructor Detail

ZooHelper

public ZooHelper()

Method Detail

ruok

public static void ruok(InetAddress addr,
                        int clientPort)
                 throws IOException

Inquires whether a zookeeper instance is running in a non-error state and returns iff the service reports "imok".

Parameters:

addr - The address of the zookeeper instance.

clientPort - The client port.

Throws:

IOException - if there is any problem communicating with the service, including a timeout (the service is not responsive).

kill

public static void kill(int clientPort)
                 throws UnknownHostException,
                        IOException

Kills a local zookeeper instance responding at the specified client port.

Parameters:

clientPort - The client port.

Throws:

IOException - if there is any problem communicating with the service, including a timeout (the service is not responsive).

UnknownHostException

stat

public static String stat(InetAddress addr,
                          int clientPort)
                   throws UnknownHostException,
                          IOException

Sends a "stat" command and return the result.

Parameters:

addr - The address of the zookeeper instance.

clientPort - The client port for zookeeper.

Returns:

The result.

Throws:

UnknownHostException - if the hostname can not be resolved.

IOException - if there is any problem communicating with the service, including a timeout (the service is not responsive).

dump

public static String dump(InetAddress addr,
                          int clientPort)
                   throws UnknownHostException,
                          IOException

Sends a "dump" command and return the result.

Parameters:

addr - The address of the zookeeper instance.

clientPort - The client port for zookeeper.

Returns:

The result.

Throws:

UnknownHostException - if the hostname can not be resolved.

IOException - if there is any problem communicating with the service, including a timeout (the service is not responsive).

isRunning

public static boolean isRunning(InetAddress addr,
                                int clientPort)

Return true if zookeeper is running on the specified host at the client port.

Returns:

true if zookeeper responds to an [ruok] request on that host and client port.

destroyZNodes

public static void destroyZNodes(org.apache.zookeeper.ZooKeeper zookeeper,
                                 String zpath,
                                 int depth)
                          throws org.apache.zookeeper.KeeperException,
                                 InterruptedException

Destroys all znodes under the specified zpath and then the znode at the specified zpath. If there is no such znode, then return immediately.

Parameters:

zookeeper -

zpath - The path to the root of the hierarchy to be destroyed.

depth - The depth (initially zero).

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

main

public static void main(String[] args)
                 throws IOException

Send four letter commands to zookeeper.

Parameters:

args - host:clientPort command

Throws:

IOException