Package org.apache.hadoop.util.curator

Class ZKCuratorManager

java.lang.Object

org.apache.hadoop.util.curator.ZKCuratorManager

@Private
public final class ZKCuratorManager
extends Object

Helper class that provides utility methods specific to ZK operations.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ZKCuratorManager.HadoopZookeeperFactory
class	ZKCuratorManager.SafeTransaction	Use curator transactions to ensure zk-operations are performed in an all or nothing fashion.

Constructor Summary

Constructors

Constructor	Description
ZKCuratorManager(Configuration config)

Method Summary

Modifier and Type	Method	Description
void	close()	Close the connection with ZooKeeper.
boolean	create(String path)	Create a ZNode.
boolean	create(String path, List<org.apache.zookeeper.data.ACL> zkAcl)	Create a ZNode.
void	createRootDirRecursively(String path)	Utility function to ensure that the configured base znode exists.
void	createRootDirRecursively(String path, List<org.apache.zookeeper.data.ACL> zkAcl)	Utility function to ensure that the configured base znode exists.
ZKCuratorManager.SafeTransaction	createTransaction(List<org.apache.zookeeper.data.ACL> fencingACL, String fencingNodePath)
boolean	delete(String path)	Delete a ZNode.
boolean	exists(String path)	Check if a ZNode exists.
List<org.apache.zookeeper.data.ACL>	getACL(String path)	Get ACLs for a ZNode.
List<String>	getChildren(String path)	Get children of a ZNode.
org.apache.curator.framework.CuratorFramework	getCurator()	Get the curator framework managing the ZooKeeper connection.
byte[]	getData(String path)	Get the data in a ZNode.
byte[]	getData(String path, org.apache.zookeeper.data.Stat stat)	Get the data in a ZNode.
static String	getNodePath(String root, String nodeName)	Get the path for a ZNode.
String	getStringData(String path)	Get the data in a ZNode.
String	getStringData(String path, org.apache.zookeeper.data.Stat stat)	Get the data in a ZNode.
static List<org.apache.zookeeper.data.ACL>	getZKAcls(Configuration conf)	Utility method to fetch the ZK ACLs from the configuration.
static List<ZKUtil.ZKAuthInfo>	getZKAuths(Configuration conf)	Utility method to fetch ZK auth info from the configuration.
void	safeCreate(String path, byte[] data, List<org.apache.zookeeper.data.ACL> acl, org.apache.zookeeper.CreateMode mode, List<org.apache.zookeeper.data.ACL> fencingACL, String fencingNodePath)
void	safeDelete(String path, List<org.apache.zookeeper.data.ACL> fencingACL, String fencingNodePath)	Deletes the path.
void	safeSetData(String path, byte[] data, int version, List<org.apache.zookeeper.data.ACL> fencingACL, String fencingNodePath)
void	setData(String path, byte[] data, int version)	Set data into a ZNode.
void	setData(String path, String data, int version)	Set data into a ZNode.
void	start()	Start the connection to the ZooKeeper ensemble.
void	start(String zkHostPort)	Start the connection to the ZooKeeper ensemble.
void	start(List<org.apache.curator.framework.AuthInfo> authInfos)	Start the connection to the ZooKeeper ensemble.
void	start(List<org.apache.curator.framework.AuthInfo> authInfos, boolean sslEnabled)	Start the connection to the ZooKeeper ensemble.
void	start(List<org.apache.curator.framework.AuthInfo> authInfos, boolean sslEnabled, String zkHostPort)	Start the connection to the ZooKeeper ensemble.

Methods inherited from class java.lang.Object

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

Constructor Details

ZKCuratorManager

public ZKCuratorManager(Configuration config)
                 throws IOException

Throws:

IOException

Method Details

getCurator

public org.apache.curator.framework.CuratorFramework getCurator()

Get the curator framework managing the ZooKeeper connection.

Returns:

Curator framework.

close

public void close()

Close the connection with ZooKeeper.

getZKAcls

public static List<org.apache.zookeeper.data.ACL> getZKAcls(Configuration conf)
                                                     throws IOException

Utility method to fetch the ZK ACLs from the configuration.

Parameters:

conf - configuration.

Returns:

acl list.

Throws:

IOException - if the Zookeeper ACLs configuration file cannot be read

getZKAuths

public static List<ZKUtil.ZKAuthInfo> getZKAuths(Configuration conf)
                                          throws IOException

Utility method to fetch ZK auth info from the configuration.

Parameters:

conf - configuration.

Returns:

ZKAuthInfo List.

Throws:

IOException - if the Zookeeper ACLs configuration file cannot be read

ZKUtil.BadAuthFormatException - if the auth format is invalid

start

public void start()
           throws IOException

Start the connection to the ZooKeeper ensemble.

Throws:

IOException - If the connection cannot be started.

start

public void start(List<org.apache.curator.framework.AuthInfo> authInfos)
           throws IOException

Start the connection to the ZooKeeper ensemble.

Parameters:

authInfos - List of authentication keys.

Throws:

IOException - If the connection cannot be started.

start

public void start(String zkHostPort)
           throws IOException

Start the connection to the ZooKeeper ensemble.

Parameters:

zkHostPort - Host:Port of the ZooKeeper.

Throws:

IOException - If the connection cannot be started.

start

public void start(List<org.apache.curator.framework.AuthInfo> authInfos,
 boolean sslEnabled)
           throws IOException

Start the connection to the ZooKeeper ensemble.

Parameters:

authInfos - List of authentication keys.

sslEnabled - If the connection should be SSL/TLS encrypted.

Throws:

IOException - If the connection cannot be started.

start

public void start(List<org.apache.curator.framework.AuthInfo> authInfos,
 boolean sslEnabled,
 String zkHostPort)
           throws IOException

Start the connection to the ZooKeeper ensemble.

Parameters:

authInfos - List of authentication keys.

sslEnabled - If the connection should be SSL/TLS encrypted.

zkHostPort - Host:Port of the ZooKeeper.

Throws:

IOException - If the connection cannot be started.

getACL

public List<org.apache.zookeeper.data.ACL> getACL(String path)
                                           throws Exception

Get ACLs for a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

The list of ACLs.

Throws:

Exception - If it cannot contact Zookeeper.

getData

public byte[] getData(String path)
               throws Exception

Get the data in a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

The data in the ZNode.

Throws:

Exception - If it cannot contact Zookeeper.

getData

public byte[] getData(String path,
 org.apache.zookeeper.data.Stat stat)
               throws Exception

Get the data in a ZNode.

Parameters:

path - Path of the ZNode.

stat - stat.

Returns:

The data in the ZNode.

Throws:

Exception - If it cannot contact Zookeeper.

getStringData

public String getStringData(String path)
                     throws Exception

Get the data in a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

The data in the ZNode.

Throws:

Exception - If it cannot contact Zookeeper.

getStringData

public String getStringData(String path,
 org.apache.zookeeper.data.Stat stat)
                     throws Exception

Get the data in a ZNode.

Parameters:

path - Path of the ZNode.

stat - Output statistics of the ZNode.

Returns:

The data in the ZNode.

Throws:

Exception - If it cannot contact Zookeeper.

setData

public void setData(String path,
 byte[] data,
 int version)
             throws Exception

Set data into a ZNode.

Parameters:

path - Path of the ZNode.

data - Data to set.

version - Version of the data to store.

Throws:

Exception - If it cannot contact Zookeeper.

setData

public void setData(String path,
 String data,
 int version)
             throws Exception

Set data into a ZNode.

Parameters:

path - Path of the ZNode.

data - Data to set as String.

version - Version of the data to store.

Throws:

Exception - If it cannot contact Zookeeper.

getChildren

public List<String> getChildren(String path)
                         throws Exception

Get children of a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

The list of children.

Throws:

Exception - If it cannot contact Zookeeper.

exists

public boolean exists(String path)
               throws Exception

Check if a ZNode exists.

Parameters:

path - Path of the ZNode.

Returns:

If the ZNode exists.

Throws:

Exception - If it cannot contact Zookeeper.

create

public boolean create(String path)
               throws Exception

Create a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

If the ZNode was created.

Throws:

Exception - If it cannot contact Zookeeper.

create

public boolean create(String path,
 List<org.apache.zookeeper.data.ACL> zkAcl)
               throws Exception

Create a ZNode.

Parameters:

path - Path of the ZNode.

zkAcl - ACL for the node.

Returns:

If the ZNode was created.

Throws:

Exception - If it cannot contact Zookeeper.

createRootDirRecursively

public void createRootDirRecursively(String path)
                              throws Exception

Utility function to ensure that the configured base znode exists. This recursively creates the znode as well as all of its parents.

Parameters:

path - Path of the znode to create.

Throws:

Exception - If it cannot create the file.

createRootDirRecursively

public void createRootDirRecursively(String path,
 List<org.apache.zookeeper.data.ACL> zkAcl)
                              throws Exception

Utility function to ensure that the configured base znode exists. This recursively creates the znode as well as all of its parents.

Parameters:

path - Path of the znode to create.

zkAcl - ACLs for ZooKeeper.

Throws:

Exception - If it cannot create the file.

delete

public boolean delete(String path)
               throws Exception

Delete a ZNode.

Parameters:

path - Path of the ZNode.

Returns:

If the znode was deleted.

Throws:

Exception - If it cannot contact ZooKeeper.

getNodePath

public static String getNodePath(String root,
 String nodeName)

Get the path for a ZNode.

Parameters:

root - Root of the ZNode.

nodeName - Name of the ZNode.

Returns:

Path for the ZNode.

safeCreate

public void safeCreate(String path,
 byte[] data,
 List<org.apache.zookeeper.data.ACL> acl,
 org.apache.zookeeper.CreateMode mode,
 List<org.apache.zookeeper.data.ACL> fencingACL,
 String fencingNodePath)
                throws Exception

Throws:

Exception

safeDelete

public void safeDelete(String path,
 List<org.apache.zookeeper.data.ACL> fencingACL,
 String fencingNodePath)
                throws Exception

Deletes the path. Checks for existence of path as well.

Parameters:

path - Path to be deleted.

fencingNodePath - fencingNodePath.

fencingACL - fencingACL.

Throws:

Exception - if any problem occurs while performing deletion.

safeSetData

public void safeSetData(String path,
 byte[] data,
 int version,
 List<org.apache.zookeeper.data.ACL> fencingACL,
 String fencingNodePath)
                 throws Exception

Throws:

Exception

createTransaction

public ZKCuratorManager.SafeTransaction createTransaction(List<org.apache.zookeeper.data.ACL> fencingACL,
 String fencingNodePath)
                                                   throws Exception

Throws:

Exception