System for dynamically replacing operating software which provides distributed directory service after verifying that versions of new software and the operating software are compatible

The present invention provides a method and apparatus for dynamically updating computer programs that are providing X.500 directory services without interruption of service. Upon receiving a call to update a computer program providing directory services, a process or thread is executed that authenticates the user making the reload request, loads a program loader, renames the then currently running directory services program, and calls another process or thread, while it awaits completion of the second process or thread. The second process or thread loads and initializes the new directory services computer program and then interacts with the program loader and the new directory services computer program to determine if the old and new directory services programs are compatible. If the old and new directory services computer programs are not compatible, the second process or thread aborts the load and transmits an abort signal to the first process or thread. If the old and the new directory services computer programs are compatible, the second process or thread transmit a commit signal to the first process or thread. The first thread upon receiving a commit signal from the second process or signal removes itself and the old directory services computer program from memory. Upon receiving an abort signal from the second process or thread, the first process or thread changes the name of the old directory services computer program back to its original name and unload itself and the loader program.