Highly available directory services in DCE

The DCE standard includes specifications for the Directory Service, a component that performs typical naming services in distributed computing environments. We list some deficiencies in these specifications that affect the naming service availability and correctness, and suggest possible solutions. We then describe an enhancement of an implementation of the Directory Service that adds support for partial replication of the name space, continuous operation of the service, and automatic fallover. Our extensions ensure the consistency of the name space data, and are transparent to application developers and end users, all without a significant performance penalty