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Overview |
  
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Overview |
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Feature availability: version 5 or above
WebORB Clustering is a logical grouping of two or more networked computers running WebORB and functioning as one from the client's perspective. The clustering feature provides automatic synchronization of any shared state between the computers included into the cluster. A cluster can be dynamic as new nodes join in or existing ones get terminated or permanently disconnected. Even though a cluster may have a single endpoint for the client applications, such as a load balancer, clients can connect to individual WebORB instances in a cluster and still access the synchronized state and resources. Consider the following scenarios:
Publish-Subscribe Messaging
Clustered WebORB instances (nodes) facilitate cluster-wide message distribution. When a message is published into a clustered destination, the WebORB server receiving the message replicates it to other instances in the cluster. As soon as the message is received by other nodes, it is delivered to the consumers connected to that node.
See Publish/Subscribe Messaging for additional information.
WebORB Data Management Synchronization
WebORB cluster provides support for cluster-wide notification of the WebORB Data Management clients (both Flex/AIR and JavaScript). The notification events delivered by WebORB to the clients include information about modified, created or deleted records. Clients receive notifications only if they have previously loaded the updated or deleted record or would have loaded the created one based on the executed queries.
See Data Management Synchronization for additional information.
RTMP Remote Shared Objects
WebORB supports clustered Remote Shared Objects used by the RTMP clients. A shared object hosted in a clustered WebORB instance is replicated through the cluster. Any changes to shared object are automatically replicated throughout all WebORB nodes. As a result, the RTMP clients connected to a clustered remote shared object will receive its synchronization updates.
See Remote Shared Objects for additional information.
Stateful Remoting Services
A stateful service in a WebORB cluster shares its state between all cluster instances. Any time a client changes the state of a stateful remoting service via a remote method invocation, all other clients have access to the service's state via subsequent method invocations. The service object does not have a precise location on the network, it is shared between several WebORB instances, but all of them have access to the object.
See Stateful Remoting Services for additional information.