org.eclipse.smila.zookeeper

Class ZkConfigurationUpdateWatcher

java.lang.Object

org.eclipse.smila.zookeeper.ZkConfigurationUpdateWatcher

All Implemented Interfaces:

ConfigurationUpdateWatcher

public class ZkConfigurationUpdateWatcher
extends java.lang.Object
implements ConfigurationUpdateWatcher

Uses ZooKeeper to coordinate configuration updating in a SMILA cluster.

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.smila.utils.config.ConfigurationUpdateWatcher

ConfigurationUpdateWatcher.UpdateableService

Constructor Summary

Constructors

Constructor and Description
ZkConfigurationUpdateWatcher()
ZkConfigurationUpdateWatcher(ZooKeeperService zkService, java.lang.String configType)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	activate(ComponentContext context) activate the service.
void	checkConfigVersions() compare cluster versions of configurations with local versions and update local deployment.
void	configDeleted(java.lang.String configurationName) Send delete notification, call on custom configuration remove.
void	configLoadedOnStart(java.lang.String configurationName, java.lang.String timestamp) Initialize notification structure for configuration, call on initial load on service start.
void	configUpdated(java.lang.String configurationName, java.lang.String timestamp) Send update notification, call on custom configuration creation or update.
void	initialize() connect to Zookeeper and create root node.
void	process(WatchedEvent event) reinstalls the watch and calls checkConfigVersions().
void	registerService(ConfigurationUpdateWatcher.UpdateableService service) register a service to be notified on configuration updates.
void	setZkService(ZooKeeperService zkService) service reference bind method.
void	startPolling() start polling for updates.
void	startPolling(int pollIntervalSeconds) start polling for updates with custom interval.
boolean	startWatching() install a ZK watch on the root node to get notifications about changes.
void	stopPolling() stop polling for updates.
void	stopWatching() stop watching: ZK watch on root node will not be reinstalled.
void	unsetZkService(ZooKeeperService zkService) service reference unbind method.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZkConfigurationUpdateWatcher

public ZkConfigurationUpdateWatcher()

ZkConfigurationUpdateWatcher

public ZkConfigurationUpdateWatcher(ZooKeeperService zkService,
                            java.lang.String configType)

Method Detail

setZkService

public void setZkService(ZooKeeperService zkService)

service reference bind method.

unsetZkService

public void unsetZkService(ZooKeeperService zkService)

service reference unbind method.

registerService

public void registerService(ConfigurationUpdateWatcher.UpdateableService service)

Description copied from interface: ConfigurationUpdateWatcher

register a service to be notified on configuration updates.

Specified by:

registerService in interface ConfigurationUpdateWatcher

activate

protected void activate(ComponentContext context)

activate the service.

initialize

public void initialize()
                throws KeeperException

connect to Zookeeper and create root node.

Throws:

KeeperException

startWatching

public boolean startWatching()

Description copied from interface: ConfigurationUpdateWatcher

install a ZK watch on the root node to get notifications about changes.

Specified by:

startWatching in interface ConfigurationUpdateWatcher

Returns:

true if watched was installed successfully

stopWatching

public void stopWatching()

Description copied from interface: ConfigurationUpdateWatcher

stop watching: ZK watch on root node will not be reinstalled. Does not remove a currently installed watch, so it's possible that remaining watches will still receive notifications after this call.

Specified by:

stopWatching in interface ConfigurationUpdateWatcher

startPolling

public void startPolling()

Description copied from interface: ConfigurationUpdateWatcher

start polling for updates.

Specified by:

startPolling in interface ConfigurationUpdateWatcher

startPolling

public void startPolling(int pollIntervalSeconds)

Description copied from interface: ConfigurationUpdateWatcher

start polling for updates with custom interval.

Specified by:

startPolling in interface ConfigurationUpdateWatcher

stopPolling

public void stopPolling()

Description copied from interface: ConfigurationUpdateWatcher

stop polling for updates.

Specified by:

stopPolling in interface ConfigurationUpdateWatcher

configLoadedOnStart

public void configLoadedOnStart(java.lang.String configurationName,
                       java.lang.String timestamp)

Description copied from interface: ConfigurationUpdateWatcher

Initialize notification structure for configuration, call on initial load on service start. Does not trigger notifications for other nodes, just ensure that the node is created.

Specified by:

configLoadedOnStart in interface ConfigurationUpdateWatcher

configUpdated

public void configUpdated(java.lang.String configurationName,
                 java.lang.String timestamp)

Description copied from interface: ConfigurationUpdateWatcher

Send update notification, call on custom configuration creation or update.

Specified by:

configUpdated in interface ConfigurationUpdateWatcher

configDeleted

public void configDeleted(java.lang.String configurationName)

Description copied from interface: ConfigurationUpdateWatcher

Send delete notification, call on custom configuration remove.

Specified by:

configDeleted in interface ConfigurationUpdateWatcher

checkConfigVersions

public void checkConfigVersions()

Description copied from interface: ConfigurationUpdateWatcher

compare cluster versions of configurations with local versions and update local deployment.

Specified by:

checkConfigVersions in interface ConfigurationUpdateWatcher

process

public void process(WatchedEvent event)

reinstalls the watch and calls checkConfigVersions().