Package org.cometd.oort

Class OortPrimaryService<R,C>

java.lang.Object

org.eclipse.jetty.util.component.AbstractLifeCycle

org.cometd.oort.OortService<R,C>

org.cometd.oort.OortPrimaryService<R,C>

Type Parameters:

R - the result type

C - the opaque context type

All Implemented Interfaces:

java.util.EventListener, org.cometd.bayeux.Bayeux.BayeuxListener, org.cometd.bayeux.server.ConfigurableServerChannel.ServerChannelListener, org.cometd.bayeux.server.ServerChannel.MessageListener, org.eclipse.jetty.util.component.LifeCycle

Direct Known Subclasses:

OortPrimaryLong

public abstract class OortPrimaryService<R,C>
extends OortService<R,C>

OortPrimaryService extends OortService to allow applications to perform actions on entities that always live in a "primary" node.

Applications may have entities that are naturally owned by any node. For example, in a chat application a chat room may be created by a user in any node, and be owned by the node the user that created it is connected to.

There are cases, however, where entities cannot be owned by any node, but instead must be owned by one node only, usually referred to as the "primary" node.

A typical example of such an entity is a unique (across the cluster) ID generator that produces IDs in the form of long - the primitive Java type - values, or a service that accesses a storage (such as a file system) that is only available on a particular node, etc.

OortPrimaryService makes easier to write services that perform actions on entities that must be owned by a single node only. There is one instance of OortPrimaryService with the same name for each node, but only one of them is the "primary". Then, applications may call getPrimaryOortURL() to get the Oort URL of the "primary" node, and pass that Oort URL to OortService.forward(String, Object, Object) as described in OortService.

Nested Class Summary

Nested classes/interfaces inherited from class org.cometd.oort.OortService

OortService.Request, OortService.Result<U>, OortService.ServerContext

Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.component.AbstractLifeCycle.AbstractLifeCycleListener, org.eclipse.jetty.util.component.AbstractLifeCycle.StopException

Nested classes/interfaces inherited from interface org.cometd.bayeux.server.ConfigurableServerChannel.ServerChannelListener

org.cometd.bayeux.server.ConfigurableServerChannel.ServerChannelListener.Weak

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.LifeCycle

org.eclipse.jetty.util.component.LifeCycle.Listener

Field Summary

Fields inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

FAILED, STARTED, STARTING, STOPPED, STOPPING

Constructor Summary

Constructors

Constructor	Description
OortPrimaryService(Oort oort, java.lang.String name, boolean primary)

Method Summary

Modifier and Type	Method	Description
protected void	doStart()
protected void	doStop()
java.lang.String	getPrimaryOortURL()
boolean	isPrimary()

Methods inherited from class org.cometd.oort.OortService

forward, getLocalSession, getName, getOort, getTimeout, onForward, onForwardFailed, onForwardMessage, onForwardSucceeded, onMessage, onResultMessage, setTimeout, toString

Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

addEventListener, getEventListeners, getState, getState, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, removeEventListener, setEventListeners, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cometd.bayeux.server.ServerChannel.MessageListener

onMessage

Constructor Detail

OortPrimaryService

public OortPrimaryService(Oort oort,
                          java.lang.String name,
                          boolean primary)

Parameters:

oort - the oort this instance is associated to

name - the name of this service

primary - whether this service lives on the "primary" node

Method Detail

isPrimary

public boolean isPrimary()

Returns:

whether this node is the "primary" node

getPrimaryOortURL

public java.lang.String getPrimaryOortURL()

Returns:

the "primary" Oort URL, or null if the "primary" node is down.

doStart

protected void doStart()
                throws java.lang.Exception

Overrides:

doStart in class OortService<R,C>

Throws:

java.lang.Exception

doStop

protected void doStop()
               throws java.lang.Exception

Overrides:

doStop in class OortService<R,C>

Throws:

java.lang.Exception