Most providers of market data feeds, including NYSE, NASDAQ, and SIAC allow delivery of market data over separate lines, and depend on the feed handler to eliminate duplicates, when both lines are delivering data without interruption of service.
To enable high availability of market data, separate FAST feed handlers, or collections of feed handlers, are configured. One collection of FAST Feed Handlers is configured to receive data from the primary line provided by the feed, and another collection of FAST Feed handlers is configured to receive data from the secondary line provided by the feed, as described earlier in this chapter.
The primary FAST Feed Handler collection (one or more feed handlers) uses a Publisher API configured to publish data over the Sybase RAP primary multicast channels; the secondary FAST Feed Handler collection uses a Publisher API configured to publish data over the Sybase RAP secondary multicast channels.
