io.druid.server.listener.announcer

Class ListenerDiscoverer

java.lang.Object

io.druid.server.listener.announcer.ListenerDiscoverer

public class ListenerDiscoverer
extends Object

Constructor Summary

Constructors

Constructor and Description
ListenerDiscoverer(org.apache.curator.framework.CuratorFramework cf, ListeningAnnouncerConfig listeningAnnouncerConfig)

Method Summary

Modifier and Type	Method and Description
Collection<String>	discoverChildren(String key_base) Discovers children of the listener key
Collection<com.google.common.net.HostAndPort>	getNewNodes(String listener_key) Get only nodes that are new since the last time getNewNodes was called (or all nodes if it has never been called)
Collection<com.google.common.net.HostAndPort>	getNodes(String listener_key) Get nodes at a particular listener.
void	start()
void	stop()

Methods inherited from class java.lang.Object

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

Constructor Detail

ListenerDiscoverer

@Inject
public ListenerDiscoverer(org.apache.curator.framework.CuratorFramework cf,
                                  ListeningAnnouncerConfig listeningAnnouncerConfig)

Method Detail

start

public void start()

stop

public void stop()

getNodes

public Collection<com.google.common.net.HostAndPort> getNodes(String listener_key)
                                                       throws IOException

Get nodes at a particular listener. This method lazily adds service discovery

Parameters:

listener_key - The Listener's service key

Returns:

A collection of druid nodes as established by the service discovery

Throws:

IOException - if there was an error refreshing the zookeeper cache

getNewNodes

public Collection<com.google.common.net.HostAndPort> getNewNodes(String listener_key)
                                                          throws IOException

Get only nodes that are new since the last time getNewNodes was called (or all nodes if it has never been called)

Parameters:

listener_key - The listener key to look for

Returns:

A collection of nodes that are new

Throws:

IOException - If there was an error in refreshing the Zookeeper cache

discoverChildren

public Collection<String> discoverChildren(@Nullable
                                           String key_base)
                                    throws IOException

Discovers children of the listener key

Parameters:

key_base - The base of the listener key, or null or empty string to get all immediate children of the listener path

Returns:

A collection of the names of the children, or empty list on NoNodeException from Curator

Throws:

IOException - from Curator

RuntimeException - for other exceptions from Curator.