Normally, in a stream based system, a client subscription delivers a lossless stream of records at a rate determined by the server’s computational capacity. For very fast servers, this rate may be throttled by the bandwidth of the network. Frequently, it is handy to allow several basic modifications to the standard lossless subscription mechanism. While many applications require a lossless stream of events delivered with minimal latency, not all clients can make use of such a data stream. Take for example, a trading dashboard, that will display several charts of market statistics. GUI widgets, that are delivered tens of thousands of updates per second, would not only fail to update in real-time, but would waste valuable network bandwidth. There is no reason for this type of client to receive data at rates that cannot be realistically rendered, or perceived by the human eye.
The Sybase Aleri Streaming Platform provides several different subscription modes, allowing individual clients to tune their subscription for optimal application performance.