Polling versus Streaming

Cymatic software can be configured to refresh market data from Betfair using either 'streaming' or 'polling'. These settings can be found by going to the File Menu | Settings | API Refresh tab. Please see the image below

Polling

Polling is the method of refreshing prices and other data by periodically sending a request to the exchange at regular intervals (e.g. every 200ms), to pull the latest data from the exchange.

Streaming

Streaming is a different method of obtaining the latest data from the exchange, by telling the exchange to push the data to the Cymatic software only when it changes. Streaming does need to send a request for new data at regular intervals, because it keeps a connection permanently open and ready to receive data automatically.

So streaming is better than polling, for 3 main reasons:

• Streaming gets the latest changes as soon as they occur, whereas polling would only get the data at the next periodic refresh interval. For polling, the minimum refresh interval in Cymatic is 200ms, whereas 'streaming' gets data instantly so reduces the minimum interval between updates to potentially zero (0ms).
• StreaminStreaming only receives the latest changes, whereas polling always receives the whole of the data even if there have not been any changes.  So less internet bandwidth and processing is needed by streaming.
• Streaming does not have to send periodic requests because it opens the connection once and then keeps it permanently open and ready to receive data.  Whereas polling has to keep sending requests for new data at regular intervals, thus using more computer processing and internet resources.

In the past, only polling was available. Streaming is the newer technology and is the recommended method to use. However it is possible to switch to polling if you prefer, by visiting the Cymatic settings.

Click below for more information about each refresh method:

Polling settings

Streaming settings