A Fault-tolerant Distributed UNIX(R) System Resource Allocator.

UNIX(R) System users have had to tolerate insecure access to nonsharable resources such as cartridge units, tape drivers and printers. As commercial applications for UNIX System software become common, more security will be a critical requirement. Software vendors price or restrict the number of concurrent users of their licensed software. These license terms are often difficult to enforce. A resource allocator can address both problems. For a single system, a robust resource allocator is simple to implement, but design of an allocator for a cluster of systems connected by a network is difficult; there are many opportunities for partial failure and incorrect behavior. This paper describes a working prototype of a fault-tolerant allocator of distributed resources. Its design is unusual in that there is no single place where a resource allocation database is maintained. Instead, servers keep information that is of local interest. Clients set up network connections to groups of servers and then negotiate among the servers for the right to allocate resources.