A Service Measure for Clustered Workstations

Abstract

The Watson computer center has a cluster of Rise System 6000s dedicated to compute intensive work. These machines are managed as a central service with disciplines similar to mainframes. Central clusters are a new challenge to computer center management because many of the old and familiar measures of service no longer apply. The task of the cluster manager is to develop new measures of service, one of which is presented in this paper. Computer center managers no longer have a monopoly on computer service. High function workstations provide computer power comparable to mainframes. For the computer center to remain viable, it must provide some added value to computer users over and above what users can provide for themselves. New measures are needed to reflect this new competition with the office workstation. The measure proposed here is Rate of Delivery Index(RODI). RODI is the sum of user compute time divided by the speed of a typical office workstation. This measure reflects the service a user receives from the computer center as an index of the service he or .The would experience from a private machine. We've used RODI successfully at Watson for capacity planning and diagnosing performance problems. This paper describes our cluster, it's configuration and briefly, how it is managed. The main theme of the paper describes the Rate of Delivery Index and illustrates how this measure is used.