org.apache.hadoop.hbase.zookeeper
Class ZKUtil

java.lang.Object
  org.apache.hadoop.hbase.zookeeper.ZKUtil

public class ZKUtil
extends java.lang.Object

Internal HBase utility class for ZooKeeper.

Contains only static methods and constants.

Methods all throw KeeperException if there is an unexpected zookeeper exception, so callers of these methods must handle appropriately. If ZK is required for the operation, the server will need to be aborted.

Nested Class Summary

static class

ZKUtil.NodeAndData Simple class to hold a node path and node data.

Constructor Summary

ZKUtil()

Method Summary

static void	applyClusterKeyToConf(org.apache.hadoop.conf.Configuration conf, java.lang.String key) Apply the settings in the given key to the given configuration, this is used to communicate with distant clusters
static void	asyncCreate(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data, org.apache.zookeeper.AsyncCallback.StringCallback cb, java.lang.Object ctx) Async creates the specified node with the specified data.
static int	checkExists(ZooKeeperWatcher zkw, java.lang.String znode) Check if the specified node exists.
static org.apache.zookeeper.ZooKeeper	connect(org.apache.hadoop.conf.Configuration conf, java.lang.String ensemble, org.apache.zookeeper.Watcher watcher)
static org.apache.zookeeper.ZooKeeper	connect(org.apache.hadoop.conf.Configuration conf, java.lang.String ensemble, org.apache.zookeeper.Watcher watcher, java.lang.String descriptor)
static org.apache.zookeeper.ZooKeeper	connect(org.apache.hadoop.conf.Configuration conf, org.apache.zookeeper.Watcher watcher) Creates a new connection to ZooKeeper, pulling settings and ensemble config from the specified configuration object using methods from ZKConfig.
static void	createAndFailSilent(ZooKeeperWatcher zkw, java.lang.String znode) Creates the specified node, if the node does not exist.
static int	createAndWatch(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data) Creates the specified node with the specified data and watches it.
static boolean	createEphemeralNodeAndWatch(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data) Set the specified znode to be an ephemeral node carrying the specified data.
static boolean	createNodeIfNotExistsAndWatch(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data) Creates the specified znode to be a persistent node carrying the specified data.
static void	createSetData(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data) Set data into node creating node if it doesn't yet exist.
static void	createWithParents(ZooKeeperWatcher zkw, java.lang.String znode) Creates the specified node and all parent nodes required for it to exist.
static void	deleteChildrenRecursively(ZooKeeperWatcher zkw, java.lang.String node) Delete all the children of the specified node but not the node itself.
static void	deleteNode(ZooKeeperWatcher zkw, java.lang.String node) Delete the specified node.
static boolean	deleteNode(ZooKeeperWatcher zkw, java.lang.String node, int version) Delete the specified node with the specified version.
static void	deleteNodeFailSilent(ZooKeeperWatcher zkw, java.lang.String node) Deletes the specified node.
static void	deleteNodeRecursively(ZooKeeperWatcher zkw, java.lang.String node) Delete the specified node and all of it's children.
static java.lang.String	dump(ZooKeeperWatcher zkw)
static byte[]	getData(ZooKeeperWatcher zkw, java.lang.String znode) Get znode data.
static byte[]	getDataAndWatch(ZooKeeperWatcher zkw, java.lang.String znode) Get the data at the specified znode and set a watch.
static HServerAddress	getDataAsAddress(ZooKeeperWatcher zkw, java.lang.String znode) Get the data at the specified znode, deserialize it as an HServerAddress, and set a watch.
static byte[]	getDataNoWatch(ZooKeeperWatcher zkw, java.lang.String znode, org.apache.zookeeper.data.Stat stat) Get the data at the specified znode without setting a watch.
static java.lang.String	getNodeName(HServerInfo serverInfo) Get the unique node-name for the specified regionserver.
static java.lang.String	getNodeName(java.lang.String path) Get the name of the current node from the specified fully-qualified path.
static int	getNumberOfChildren(ZooKeeperWatcher zkw, java.lang.String znode) Get the number of children of the specified node.
static java.lang.String	getParent(java.lang.String node) Returns the full path of the immediate parent of the specified node.
static java.lang.String[]	getServerStats(java.lang.String server) Gets the statistics from the given server.
static java.lang.String[]	getServerStats(java.lang.String server, int timeout) Gets the statistics from the given server.
static java.lang.String	getZooKeeperClusterKey(org.apache.hadoop.conf.Configuration conf) Get the key to the ZK ensemble for this configuration without adding a name at the end
static java.lang.String	getZooKeeperClusterKey(org.apache.hadoop.conf.Configuration conf, java.lang.String name) Get the key to the ZK ensemble for this configuration and append a name at the end
static java.lang.String	joinZNode(java.lang.String prefix, java.lang.String suffix) Join the prefix znode name with the suffix znode name to generate a proper full znode name.
static java.util.List<HServerAddress>	listChildrenAndGetAsAddresses(ZooKeeperWatcher zkw, java.lang.String znode) Lists the children of the specified znode, retrieving the data of each child as a server address.
static java.util.List<java.lang.String>	listChildrenAndWatchForNewChildren(ZooKeeperWatcher zkw, java.lang.String znode) Lists the children znodes of the specified znode.
static java.util.List<java.lang.String>	listChildrenAndWatchThem(ZooKeeperWatcher zkw, java.lang.String znode) List all the children of the specified znode, setting a watch for children changes and also setting a watch on every individual child in order to get the NodeCreated and NodeDeleted events.
static java.util.List<java.lang.String>	listChildrenNoWatch(ZooKeeperWatcher zkw, java.lang.String znode) Lists the children of the specified znode without setting any watches.
static boolean	nodeHasChildren(ZooKeeperWatcher zkw, java.lang.String znode) Checks if the specified znode has any children.
static boolean	setAddressAndWatch(ZooKeeperWatcher zkw, java.lang.String znode, HServerAddress address) Set the specified znode to be an ephemeral node carrying the specified server address.
static void	setData(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data) Sets the data of the existing znode to be the specified data.
static boolean	setData(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data, int expectedVersion) Sets the data of the existing znode to be the specified data.
static java.lang.String[]	transformClusterKey(java.lang.String key) Separate the given key into the three configurations it should contain: hbase.zookeeper.quorum, hbase.zookeeper.client.port and zookeeper.znode.parent
static void	updateExistingNodeData(ZooKeeperWatcher zkw, java.lang.String znode, byte[] data, int expectedVersion) Update the data of an existing node with the expected version to have the specified data.
static boolean	watchAndCheckExists(ZooKeeperWatcher zkw, java.lang.String znode) Watch the specified znode for delete/create/change events.
static java.util.List<ZKUtil.NodeAndData>	watchAndGetNewChildren(ZooKeeperWatcher zkw, java.lang.String baseNode) Atomically add watches and read data from all unwatched unassigned nodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZKUtil

public ZKUtil()

Method Detail

connect

public static org.apache.zookeeper.ZooKeeper connect(org.apache.hadoop.conf.Configuration conf,
                                                     org.apache.zookeeper.Watcher watcher)
                                              throws java.io.IOException

Creates a new connection to ZooKeeper, pulling settings and ensemble config from the specified configuration object using methods from ZKConfig. Sets the connection status monitoring watcher to the specified watcher.

Parameters:

conf - configuration to pull ensemble and other settings from

watcher - watcher to monitor connection changes

Returns:

connection to zookeeper

Throws:

java.io.IOException - if unable to connect to zk or config problem

connect

public static org.apache.zookeeper.ZooKeeper connect(org.apache.hadoop.conf.Configuration conf,
                                                     java.lang.String ensemble,
                                                     org.apache.zookeeper.Watcher watcher)
                                              throws java.io.IOException

Throws:

java.io.IOException

connect

public static org.apache.zookeeper.ZooKeeper connect(org.apache.hadoop.conf.Configuration conf,
                                                     java.lang.String ensemble,
                                                     org.apache.zookeeper.Watcher watcher,
                                                     java.lang.String descriptor)
                                              throws java.io.IOException

Throws:

java.io.IOException

joinZNode

public static java.lang.String joinZNode(java.lang.String prefix,
                                         java.lang.String suffix)

Join the prefix znode name with the suffix znode name to generate a proper full znode name. Assumes prefix does not end with slash and suffix does not begin with it.

Parameters:

prefix - beginning of znode name

suffix - ending of znode name

Returns:

result of properly joining prefix with suffix

getParent

public static java.lang.String getParent(java.lang.String node)

Returns the full path of the immediate parent of the specified node.

Parameters:

node - path to get parent of

Returns:

parent of path, null if passed the root node or an invalid node

getNodeName

public static java.lang.String getNodeName(HServerInfo serverInfo)

Get the unique node-name for the specified regionserver. Used when a server puts up an ephemeral node for itself and needs to use a unique name.

Parameters:

serverInfo - server information

Returns:

unique, zookeeper-safe znode path for the server instance

getNodeName

public static java.lang.String getNodeName(java.lang.String path)

Get the name of the current node from the specified fully-qualified path.

Parameters:

path - fully-qualified path

Returns:

name of the current node

getZooKeeperClusterKey

public static java.lang.String getZooKeeperClusterKey(org.apache.hadoop.conf.Configuration conf)

Get the key to the ZK ensemble for this configuration without adding a name at the end

Parameters:

conf - Configuration to use to build the key

Returns:

ensemble key without a name

getZooKeeperClusterKey

public static java.lang.String getZooKeeperClusterKey(org.apache.hadoop.conf.Configuration conf,
                                                      java.lang.String name)

Get the key to the ZK ensemble for this configuration and append a name at the end

Parameters:

conf - Configuration to use to build the key

name - Name that should be appended at the end if not empty or null

Returns:

ensemble key with a name (if any)

applyClusterKeyToConf

public static void applyClusterKeyToConf(org.apache.hadoop.conf.Configuration conf,
                                         java.lang.String key)
                                  throws java.io.IOException

Apply the settings in the given key to the given configuration, this is used to communicate with distant clusters

Parameters:

conf - configuration object to configure

key - string that contains the 3 required configuratins

Throws:

java.io.IOException

transformClusterKey

public static java.lang.String[] transformClusterKey(java.lang.String key)
                                              throws java.io.IOException

Separate the given key into the three configurations it should contain: hbase.zookeeper.quorum, hbase.zookeeper.client.port and zookeeper.znode.parent

Parameters:

key -

Returns:

the three configuration in the described order

Throws:

java.io.IOException

watchAndCheckExists

public static boolean watchAndCheckExists(ZooKeeperWatcher zkw,
                                          java.lang.String znode)
                                   throws org.apache.zookeeper.KeeperException

Watch the specified znode for delete/create/change events. The watcher is set whether or not the node exists. If the node already exists, the method returns true. If the node does not exist, the method returns false.

Parameters:

zkw - zk reference

znode - path of node to watch

Returns:

true if znode exists, false if does not exist or error

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

checkExists

public static int checkExists(ZooKeeperWatcher zkw,
                              java.lang.String znode)
                       throws org.apache.zookeeper.KeeperException

Check if the specified node exists. Sets no watches. Returns true if node exists, false if not. Returns an exception if there is an unexpected zookeeper exception.

Parameters:

zkw - zk reference

znode - path of node to watch

Returns:

version of the node if it exists, -1 if does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

listChildrenAndWatchForNewChildren

public static java.util.List<java.lang.String> listChildrenAndWatchForNewChildren(ZooKeeperWatcher zkw,
                                                                                  java.lang.String znode)
                                                                           throws org.apache.zookeeper.KeeperException

Lists the children znodes of the specified znode. Also sets a watch on the specified znode which will capture a NodeDeleted event on the specified znode as well as NodeChildrenChanged if any children of the specified znode are created or deleted. Returns null if the specified node does not exist. Otherwise returns a list of children of the specified node. If the node exists but it has no children, an empty list will be returned.

Parameters:

zkw - zk reference

znode - path of node to list and watch children of

Returns:

list of children of the specified node, an empty list if the node exists but has no children, and null if the node does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

listChildrenAndWatchThem

public static java.util.List<java.lang.String> listChildrenAndWatchThem(ZooKeeperWatcher zkw,
                                                                        java.lang.String znode)
                                                                 throws org.apache.zookeeper.KeeperException

List all the children of the specified znode, setting a watch for children changes and also setting a watch on every individual child in order to get the NodeCreated and NodeDeleted events.

Parameters:

zkw - zookeeper reference

znode - node to get children of and watch

Returns:

list of znode names, null if the node doesn't exist

Throws:

org.apache.zookeeper.KeeperException

listChildrenAndGetAsAddresses

public static java.util.List<HServerAddress> listChildrenAndGetAsAddresses(ZooKeeperWatcher zkw,
                                                                           java.lang.String znode)
                                                                    throws org.apache.zookeeper.KeeperException

Lists the children of the specified znode, retrieving the data of each child as a server address. Used to list the currently online regionservers and their addresses. Sets no watches at all, this method is best effort. Returns an empty list if the node has no children. Returns null if the parent node itself does not exist.

Parameters:

zkw - zookeeper reference

znode - node to get children of as addresses

Returns:

list of data of children of specified znode, empty if no children, null if parent does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

listChildrenNoWatch

public static java.util.List<java.lang.String> listChildrenNoWatch(ZooKeeperWatcher zkw,
                                                                   java.lang.String znode)
                                                            throws org.apache.zookeeper.KeeperException

Lists the children of the specified znode without setting any watches. Used to list the currently online regionservers and their addresses. Sets no watches at all, this method is best effort. Returns an empty list if the node has no children. Returns null if the parent node itself does not exist.

Parameters:

zkw - zookeeper reference

znode - node to get children of as addresses

Returns:

list of data of children of specified znode, empty if no children, null if parent does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

watchAndGetNewChildren

public static java.util.List<ZKUtil.NodeAndData> watchAndGetNewChildren(ZooKeeperWatcher zkw,
                                                                        java.lang.String baseNode)
                                                                 throws org.apache.zookeeper.KeeperException

Atomically add watches and read data from all unwatched unassigned nodes.

This works because master is the only person deleting nodes.

Throws:

org.apache.zookeeper.KeeperException

nodeHasChildren

public static boolean nodeHasChildren(ZooKeeperWatcher zkw,
                                      java.lang.String znode)
                               throws org.apache.zookeeper.KeeperException

Checks if the specified znode has any children. Sets no watches. Returns true if the node exists and has children. Returns false if the node does not exist or if the node does not have any children. Used during master initialization to determine if the master is a failed-over-to master or the first master during initial cluster startup. If the directory for regionserver ephemeral nodes is empty then this is a cluster startup, if not then it is not cluster startup.

Parameters:

zkw - zk reference

znode - path of node to check for children of

Returns:

true if node has children, false if not or node does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

getNumberOfChildren

public static int getNumberOfChildren(ZooKeeperWatcher zkw,
                                      java.lang.String znode)
                               throws org.apache.zookeeper.KeeperException

Get the number of children of the specified node. If the node does not exist or has no children, returns 0. Sets no watches at all.

Parameters:

zkw - zk reference

znode - path of node to count children of

Returns:

number of children of specified node, 0 if none or parent does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

getData

public static byte[] getData(ZooKeeperWatcher zkw,
                             java.lang.String znode)
                      throws org.apache.zookeeper.KeeperException

Get znode data. Does not set a watcher.

Returns:

ZNode data

Throws:

org.apache.zookeeper.KeeperException

getDataAndWatch

public static byte[] getDataAndWatch(ZooKeeperWatcher zkw,
                                     java.lang.String znode)
                              throws org.apache.zookeeper.KeeperException

Get the data at the specified znode and set a watch. Returns the data and sets a watch if the node exists. Returns null and no watch is set if the node does not exist or there is an exception.

Parameters:

zkw - zk reference

znode - path of node

Returns:

data of the specified znode, or null

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

getDataNoWatch

public static byte[] getDataNoWatch(ZooKeeperWatcher zkw,
                                    java.lang.String znode,
                                    org.apache.zookeeper.data.Stat stat)
                             throws org.apache.zookeeper.KeeperException

Get the data at the specified znode without setting a watch. Returns the data if the node exists. Returns null if the node does not exist. Sets the stats of the node in the passed Stat object. Pass a null stat if not interested.

Parameters:

zkw - zk reference

znode - path of node

stat - node status to set if node exists

Returns:

data of the specified znode, or null if does not exist

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

getDataAsAddress

public static HServerAddress getDataAsAddress(ZooKeeperWatcher zkw,
                                              java.lang.String znode)
                                       throws org.apache.zookeeper.KeeperException

Get the data at the specified znode, deserialize it as an HServerAddress, and set a watch. Returns the data as a server address and sets a watch if the node exists. Returns null and no watch is set if the node does not exist or there is an exception.

Parameters:

zkw - zk reference

znode - path of node

Returns:

data of the specified node as a server address, or null

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

updateExistingNodeData

public static void updateExistingNodeData(ZooKeeperWatcher zkw,
                                          java.lang.String znode,
                                          byte[] data,
                                          int expectedVersion)
                                   throws org.apache.zookeeper.KeeperException

Update the data of an existing node with the expected version to have the specified data. Throws an exception if there is a version mismatch or some other problem. Sets no watches under any conditions.

Parameters:

zkw - zk reference

znode -

data -

expectedVersion -

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

KeeperException.BadVersionException - if version mismatch

setAddressAndWatch

public static boolean setAddressAndWatch(ZooKeeperWatcher zkw,
                                         java.lang.String znode,
                                         HServerAddress address)
                                  throws org.apache.zookeeper.KeeperException

Set the specified znode to be an ephemeral node carrying the specified server address. Used by masters for their ephemeral node and regionservers for their ephemeral node. If the node is created successfully, a watcher is also set on the node. If the node is not created successfully because it already exists, this method will also set a watcher on the node. If there is another problem, a KeeperException will be thrown.

Parameters:

zkw - zk reference

znode - path of node

address - server address

Returns:

true if address set, false if not, watch set in both cases

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

setData

public static boolean setData(ZooKeeperWatcher zkw,
                              java.lang.String znode,
                              byte[] data,
                              int expectedVersion)
                       throws org.apache.zookeeper.KeeperException,
                              org.apache.zookeeper.KeeperException.NoNodeException

Sets the data of the existing znode to be the specified data. Ensures that the current data has the specified expected version.

If the node does not exist, a KeeperException.NoNodeException will be thrown.

If their is a version mismatch, method returns null.

No watches are set but setting data will trigger other watchers of this node.

If there is another problem, a KeeperException will be thrown.

Parameters:

zkw - zk reference

znode - path of node

data - data to set for node

expectedVersion - version expected when setting data

Returns:

true if data set, false if version mismatch

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

org.apache.zookeeper.KeeperException.NoNodeException

createSetData

public static void createSetData(ZooKeeperWatcher zkw,
                                 java.lang.String znode,
                                 byte[] data)
                          throws org.apache.zookeeper.KeeperException

Set data into node creating node if it doesn't yet exist. Does not set watch.

Parameters:

zkw - zk reference

znode - path of node

data - data to set for node

Throws:

org.apache.zookeeper.KeeperException

setData

public static void setData(ZooKeeperWatcher zkw,
                           java.lang.String znode,
                           byte[] data)
                    throws org.apache.zookeeper.KeeperException,
                           org.apache.zookeeper.KeeperException.NoNodeException

Sets the data of the existing znode to be the specified data. The node must exist but no checks are done on the existing data or version.

If the node does not exist, a KeeperException.NoNodeException will be thrown.

No watches are set but setting data will trigger other watchers of this node.

If there is another problem, a KeeperException will be thrown.

Parameters:

zkw - zk reference

znode - path of node

data - data to set for node

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

org.apache.zookeeper.KeeperException.NoNodeException

createEphemeralNodeAndWatch

public static boolean createEphemeralNodeAndWatch(ZooKeeperWatcher zkw,
                                                  java.lang.String znode,
                                                  byte[] data)
                                           throws org.apache.zookeeper.KeeperException

Set the specified znode to be an ephemeral node carrying the specified data. If the node is created successfully, a watcher is also set on the node. If the node is not created successfully because it already exists, this method will also set a watcher on the node. If there is another problem, a KeeperException will be thrown.

Parameters:

zkw - zk reference

znode - path of node

data - data of node

Returns:

true if node created, false if not, watch set in both cases

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

createNodeIfNotExistsAndWatch

public static boolean createNodeIfNotExistsAndWatch(ZooKeeperWatcher zkw,
                                                    java.lang.String znode,
                                                    byte[] data)
                                             throws org.apache.zookeeper.KeeperException

Creates the specified znode to be a persistent node carrying the specified data. Returns true if the node was successfully created, false if the node already existed. If the node is created successfully, a watcher is also set on the node. If the node is not created successfully because it already exists, this method will also set a watcher on the node but return false. If there is another problem, a KeeperException will be thrown.

Parameters:

zkw - zk reference

znode - path of node

data - data of node

Returns:

true if node created, false if not, watch set in both cases

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

createAndWatch

public static int createAndWatch(ZooKeeperWatcher zkw,
                                 java.lang.String znode,
                                 byte[] data)
                          throws org.apache.zookeeper.KeeperException,
                                 org.apache.zookeeper.KeeperException.NodeExistsException

Creates the specified node with the specified data and watches it.

Throws an exception if the node already exists.

The node created is persistent and open access.

Returns the version number of the created node if successful.

Parameters:

zkw - zk reference

znode - path of node to create

data - data of node to create

Returns:

version of node created

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

KeeperException.NodeExistsException - if node already exists

asyncCreate

public static void asyncCreate(ZooKeeperWatcher zkw,
                               java.lang.String znode,
                               byte[] data,
                               org.apache.zookeeper.AsyncCallback.StringCallback cb,
                               java.lang.Object ctx)
                        throws org.apache.zookeeper.KeeperException,
                               org.apache.zookeeper.KeeperException.NodeExistsException

Async creates the specified node with the specified data.

Throws an exception if the node already exists.

The node created is persistent and open access.

Parameters:

zkw - zk reference

znode - path of node to create

data - data of node to create

cb -

ctx -

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

KeeperException.NodeExistsException - if node already exists

createAndFailSilent

public static void createAndFailSilent(ZooKeeperWatcher zkw,
                                       java.lang.String znode)
                                throws org.apache.zookeeper.KeeperException

Creates the specified node, if the node does not exist. Does not set a watch and fails silently if the node already exists. The node created is persistent and open access.

Parameters:

zkw - zk reference

znode - path of node

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

createWithParents

public static void createWithParents(ZooKeeperWatcher zkw,
                                     java.lang.String znode)
                              throws org.apache.zookeeper.KeeperException

Creates the specified node and all parent nodes required for it to exist. No watches are set and no errors are thrown if the node already exists. The nodes created are persistent and open access.

Parameters:

zkw - zk reference

znode - path of node

Throws:

org.apache.zookeeper.KeeperException - if unexpected zookeeper exception

deleteNode

public static void deleteNode(ZooKeeperWatcher zkw,
                              java.lang.String node)
                       throws org.apache.zookeeper.KeeperException

Delete the specified node. Sets no watches. Throws all exceptions.

Throws:

org.apache.zookeeper.KeeperException

deleteNode

public static boolean deleteNode(ZooKeeperWatcher zkw,
                                 java.lang.String node,
                                 int version)
                          throws org.apache.zookeeper.KeeperException

Delete the specified node with the specified version. Sets no watches. Throws all exceptions.

Throws:

org.apache.zookeeper.KeeperException

deleteNodeFailSilent

public static void deleteNodeFailSilent(ZooKeeperWatcher zkw,
                                        java.lang.String node)
                                 throws org.apache.zookeeper.KeeperException

Deletes the specified node. Fails silent if the node does not exist.

Parameters:

zkw -

node -

Throws:

org.apache.zookeeper.KeeperException

deleteNodeRecursively

public static void deleteNodeRecursively(ZooKeeperWatcher zkw,
                                         java.lang.String node)
                                  throws org.apache.zookeeper.KeeperException

Delete the specified node and all of it's children. Sets no watches. Throws all exceptions besides dealing with deletion of children.

Throws:

org.apache.zookeeper.KeeperException

deleteChildrenRecursively

public static void deleteChildrenRecursively(ZooKeeperWatcher zkw,
                                             java.lang.String node)
                                      throws org.apache.zookeeper.KeeperException

Delete all the children of the specified node but not the node itself. Sets no watches. Throws all exceptions besides dealing with deletion of children.

Throws:

org.apache.zookeeper.KeeperException

dump

public static java.lang.String dump(ZooKeeperWatcher zkw)

Returns:

String dump of everything in ZooKeeper.

getServerStats

public static java.lang.String[] getServerStats(java.lang.String server)
                                         throws java.io.IOException

Gets the statistics from the given server. Uses a 1 minute timeout.

Parameters:

server - The server to get the statistics from.

Returns:

The array of response strings.

Throws:

java.io.IOException - When the socket communication fails.

getServerStats

public static java.lang.String[] getServerStats(java.lang.String server,
                                                int timeout)
                                         throws java.io.IOException

Gets the statistics from the given server.

Parameters:

server - The server to get the statistics from.

timeout - The socket timeout to use.

Returns:

The array of response strings.

Throws:

java.io.IOException - When the socket communication fails.