1. A system for delivering data to a client application over a network, the system comprising: a server in data communication with the network; a client in data communication with the server via the network, a client application executing on the client; a scalable message queuing system in data communication with the server and the client via the network, the scalable message queuing system including a plurality of gateway nodes configured to receive connections from the client over the network, a plurality of queue nodes containing subscription information about queue subscribers, and a consistent hash table mapping a queue identifier requested on a gateway node to a corresponding queue node for the requested queue identifier; the client being configured to request, for the client application, data associated with a data identifier from the server, the request including a header to signal the server that the client requests receipt of real-time invalidation information associated with the requested data, the data identifier including a uniform resource identifier (URI); the server being configured to provide the data associated with the data identifier, the data being subject to subsequent change, the server being further configured to establish a queue associated with the data identifier at the scalable message queuing system, a queue identifier corresponding to the established queue being returned to the client; the client being further configured to subscribe to the queue corresponding to the queue identifier at the scalable message queuing system using the returned queue identifier to receive invalidation information associated with the data; the server being further configured to signal the queue corresponding to the queue identifier of an invalidation event associated with the data in response to receiving the header to signal the server that the client requests receipt of real-time invalidation information associated with the requested data; the scalable message queuing system being configured to convey information indicative of the invalidation event of the queue corresponding to the queue identifier to the subscribed client in response to receiving the signal of the invalidation event associated with the queue corresponding to the queue identifier from the server; and the client being further configured to re-request the data associated with the data identifier from the server upon receipt of the information indicative of the invalidation event from the queue corresponding to the queue identifier of the scalable message queuing system.