ml.shifu.guagua.coordinator.zk

Class ZooKeeperUtils

java.lang.Object

ml.shifu.guagua.coordinator.zk.ZooKeeperUtils

public final class ZooKeeperUtils
extends Object

ZooKeeperUtils is a helper used to start embed zookeeper server in CLI host.

For big data guagua application, independent zookeeper instance is recommended, embed server is for user easy to use guagua if there is no zookeeper server in hand.

Field Summary

Fields

Modifier and Type	Field and Description
static int	INITAL_ZK_PORT Initial zookeeper port used for check valid zookeeper port.
static int	RETRY_COUNT Client connection retry count
static int	TRY_PORT_COUNT How many ports will be used to launch embed zookeeper server.

Method Summary

Modifier and Type	Method and Description
static void	checkIfEmbedZooKeeperStarted(int embedZkClientPort) Wait for a time period until zookeeper server is started.
static boolean	checkServers(String servers) Check zookeeper servers, if one of them is alive, return true;
static String	findContainingJar(Class my_class) Find a jar that contains a class of the same name, if any.
static int	getValidZooKeeperPort() Check from DEFAULT_ZK_PORT to (DEFAULT_ZK_PORT + TRY_PORT_COUNT) to see if there is valid port to launch embed zookeeper server.
static boolean	isServerAlive(InetAddress host, int port) Check whether a server is alive.
static boolean	isServerAlive(String host, int port) Check whether a server is alive.
static void	populateZooKeeperConfFile(String fileName, Map<String,String> props) Create zoo.cfg file to launch a embed zookeeper server.
static void	prepZooKeeperConf(String zkFolder, String fileName, String clientPort) Create zookeeper file with specified name and client port setting.
static String	startChildZooKeeperProcess(String zkJavaOpts) Start embed zookeeper server in a child process.
static int	startEmbedZooKeeper() Start embed zookeeper server in a daemon thread.

Methods inherited from class java.lang.Object

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

Field Detail

RETRY_COUNT

public static final int RETRY_COUNT

Client connection retry count

See Also:

Constant Field Values

TRY_PORT_COUNT

public static final int TRY_PORT_COUNT

How many ports will be used to launch embed zookeeper server.

See Also:

Constant Field Values

INITAL_ZK_PORT

public static final int INITAL_ZK_PORT

Initial zookeeper port used for check valid zookeeper port.

See Also:

Constant Field Values

Method Detail

getValidZooKeeperPort

public static int getValidZooKeeperPort()

Check from DEFAULT_ZK_PORT to (DEFAULT_ZK_PORT + TRY_PORT_COUNT) to see if there is valid port to launch embed zookeeper server.

Returns:

valid zookeeper port

populateZooKeeperConfFile

public static void populateZooKeeperConfFile(String fileName,
                                             Map<String,String> props)

Create zoo.cfg file to launch a embed zookeeper server.

Parameters:

fileName - zookeeper conf file name

props - key-value pairs for zookeeper configurations

isServerAlive

public static boolean isServerAlive(InetAddress host,
                                    int port)

Check whether a server is alive.

Parameters:

host - the server host

port - the server port

Returns:

true if a server is alive, false if a server is not alive.

isServerAlive

public static boolean isServerAlive(String host,
                                    int port)

Check whether a server is alive.

Parameters:

host - the server host

port - the server port

Returns:

true if a server is alive, false if a server is not alive.

prepZooKeeperConf

public static void prepZooKeeperConf(String zkFolder,
                                     String fileName,
                                     String clientPort)
                              throws IOException

Create zookeeper file with specified name and client port setting.

Throws:

IOException

checkIfEmbedZooKeeperStarted

public static void checkIfEmbedZooKeeperStarted(int embedZkClientPort)

Wait for a time period until zookeeper server is started.

Parameters:

embedZkClientPort - the valid zookeeper client port

startEmbedZooKeeper

public static int startEmbedZooKeeper()
                               throws IOException

Start embed zookeeper server in a daemon thread.

Throws:

IOException

startChildZooKeeperProcess

public static String startChildZooKeeperProcess(String zkJavaOpts)
                                         throws IOException

Start embed zookeeper server in a child process.

Returns:

null if start child process failed, non empty string if valid zookeeper server in child.

Throws:

IOException

findContainingJar

public static String findContainingJar(Class my_class)

Find a jar that contains a class of the same name, if any. It will return a jar file, even if that is not the first thing on the class path that has a class with the same name.

Parameters:

my_class - the class to find

Returns:

a jar file that contains the class, or null

checkServers

public static boolean checkServers(String servers)

Check zookeeper servers, if one of them is alive, return true;