Maintaining the time in a distributed system

To a client of a loosely-coupled distr ibuted system, one of the simplest services is a time service. Usually the client simply requests the t ime from an) subset of the time servers making up the service, and uses the first reply. Issues that need to be considered in other services, such as connection establ ishment or client authenticat ion, need not be c,ms:dered in a time service. The simplicity of t~.,, int, ,action. however. misrepresents the complexity of ~mplementing such a service.