Push Technology Overview

Push technology is a model of Internet-based communication in which information transfer is initiated from a server to the client. Also called the publish/subscribe model, this type of communication is the opposite of pull technology in which a request for information is made from a client to the server. The information that’s sent by the server is typically specified in advance. When using Streaming API, you specify the information the client receives by creating a PushTopic. The client then subscribes to the PushTopic channel to be notified of events that match the PushTopic criteria.

In push technology, the server pushes out information to the client after the client has subscribed to a channel of information. In order for the client to receive the information, the client must maintain a connection to the server. Streaming API uses the Bayeux protocol and CometD, so the client to server connection is maintained through long polling.