Now that it has an Object Request Broker under its belt (CI No 2,734), Isis Distributed Systems Inc, Marlborough, Massachusetts, this week moves its high-availability replication software into the database world as Isis for Database, in Oracle and Sybase versions. Instead of using the add-on Oracle and Sybase replication modules, which copy data to a primary and, subsequently to secondary databases, Isis said users that want continuous availability should buy its code, which can update, balance queries and restore application and data across multiple databases simultaneously. The company said in the other mechanism there is a possibility of failure and therefore loss of integrity. Less than 1% of an application’s code would have to be written to Isis application programming interfaces, the company claimed, saying it aims one day to make its mechanism completely transparent. The Isis software replicates application processes and data to two or more database locations and partitions application logic and the user interface between other servers and clients. Isis’s key technology is 100,000 or so lines of code that grew out of a Cornell University project. It builds Isis’s own protocol on TCP/IP’s User Datagram Protocol, UDP, layer, acting as a kind of flow metre, regulating sends and responses to guaranteeing delivery. The implem entation isn’t database-specific – it has SQL Server and object database versions in the wings. For developers it costs $9,000 per user, a run-time licence is $10,000, for SunOS, Solaris, AIX and HP-UX.
