R
- the result typeC
- the opaque context typepublic abstract class OortMasterService<R,C> extends OortService<R,C>
OortMasterService
extends OortService
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 of OortMasterService
with the same name for each
node, but only one of them is the "master".
Then, applications may call getMasterOortURL()
to get the Oort URL
of the "master" node, and pass that Oort URL to
OortService.forward(String, Object, Object)
as described in OortService
.
OortService.Request, OortService.Result<U>, OortService.ServerContext
org.eclipse.jetty.util.component.AbstractLifeCycle.AbstractLifeCycleListener
logger
Constructor and Description |
---|
OortMasterService(Oort oort,
String name,
boolean master) |
Modifier and Type | Method and Description |
---|---|
protected void |
doStart() |
protected void |
doStop() |
String |
getMasterOortURL() |
boolean |
isMaster() |
forward, getLocalSession, getName, getOort, getTimeout, onForward, onForwardFailed, onForwardMessage, onForwardSucceeded, onMessage, onResultMessage, setTimeout, toString
public boolean isMaster()
public String getMasterOortURL()
protected void doStart() throws Exception
doStart
in class OortService<R,C>
Exception
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