Distributed data access system including a plurality of database access processors with one-for-N redundancy

A system for selectively distributing securities market transaction information to users, comprising:

• a communication structure for routing information to users;
• a plurality of first, substantially identical computer facilities connected to the communication structure for receiving and storing securities information, each of the first computer facilities including:
• a respective connection to the communication structure;
• and
• a respective set of user connectivity data structures which identify users served by the first computer facility, define communications routing paths through the communication structure to users served by the first computer facility, and identify securities for which users in the users served by the first computer facility have submitted monitor requests;
• at least one spare first computer facility, substantially identical with the plurality of first computer facilities, but without a set of user connectivity data structures;
• and
• an arbitrator computer facility connected to the communication structure for:
• detecting a failed first computer facility;
• and
• configuring the spare computer facility to serve users served by the failed computer facility by providing to the spare computer facility the set of user connectivity data structures of the failed computer facility.

A method providing computer redundancy in a system which distributes securities information to a plurality of users through a plurality of substantially identical computer facilities and includes a communication facility connected to the computer facilities which routes securities information from each computer facility to a respective set of users, the method including the steps of:

• providing a spare computer facility substantially identical to the plurality of computer facilities;
• connecting the spare computer facility to the communication facility;
• maintaining at each computer facility except the spare computer facility a set of connectivity data structures which define communication routing paths through the communication structure between the computer facility and users of a set of users served by the computer facility;
• periodically obtaining sets of connectivity data structures from the computer facilities except the spare computer facility;
• storing the sets of connectivity data structures in a single archive database separate from all of the computer facilities including the spare computer facility;
• periodically testing the level of operation of all of the computer facilities;
• detecting a failed computer facility in response to the testing step;
• and
• substituting the spare computer facility for the failed computer facility by transferring to the spare computer facility a set of connectivity data structures for the failed computer facility from the archive database.