Class OortMasterService<R,C>
- java.lang.Object
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- org.eclipse.jetty.util.component.AbstractLifeCycle
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- org.cometd.oort.OortService<R,C>
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- org.cometd.oort.OortMasterService<R,C>
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- Type Parameters:
R
- the result typeC
- 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:
OortMasterLong
public abstract class OortMasterService<R,C> extends OortService<R,C>
OortMasterService
extendsOortService
to allow applications to perform actions on entities that always live in a "master" 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 "master" 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.OortMasterService
makes easier to write services that perform actions on entities that must be owned by a single node only. There is one instance ofOortMasterService
with the same name for each node, but only one of them is the "master". Then, applications may callgetMasterOortURL()
to get the Oort URL of the "master" node, and pass that Oort URL toOortService.forward(String, Object, Object)
as described inOortService
.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.cometd.oort.OortService
OortService.Request, OortService.Result<U>, OortService.ServerContext
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Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle
org.eclipse.jetty.util.component.AbstractLifeCycle.AbstractLifeCycleListener
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Field Summary
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Fields inherited from class org.cometd.oort.OortService
logger
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Constructor Summary
Constructors Constructor Description OortMasterService(Oort oort, java.lang.String name, boolean master)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected void
doStart()
protected void
doStop()
java.lang.String
getMasterOortURL()
boolean
isMaster()
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Methods inherited from class org.cometd.oort.OortService
forward, getLocalSession, getName, getOort, getTimeout, onForward, onForwardFailed, onForwardMessage, onForwardSucceeded, onMessage, onResultMessage, setTimeout, toString
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Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle
addLifeCycleListener, getState, getState, getStopTimeout, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, removeLifeCycleListener, setStopTimeout, start, stop
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Constructor Detail
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OortMasterService
public OortMasterService(Oort oort, java.lang.String name, boolean master)
- Parameters:
oort
- the oort this instance is associated toname
- the name of this servicemaster
- whether this service lives on the "master" node
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Method Detail
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isMaster
public boolean isMaster()
- Returns:
- whether this node is the "master" node
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getMasterOortURL
public java.lang.String getMasterOortURL()
- Returns:
- the "master" Oort URL, or null if the "master" node is down.
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doStart
protected void doStart() throws java.lang.Exception
- Overrides:
doStart
in classOortService<R,C>
- Throws:
java.lang.Exception
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doStop
protected void doStop() throws java.lang.Exception
- Overrides:
doStop
in classOortService<R,C>
- Throws:
java.lang.Exception
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