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Multiple message processors can use the same message store. For example, in a clustered environment, each of the nodes might have an instance of the same message processor, each of which would connect to the same message store and evenly consume messages from it. The message store acts as a manager of these consumers and their connections and ensures that messages are processed by only one message processor, preventing message duplication. You can further control which nodes a message processor runs on by specifying pinned servers, so that you might have each message processor run on one node only, as shown in the following diagram.
The ESB ships with the following message processor implementations:
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