  Monitoring and information services form a key component of a distributed
system, or Grid. A quantitative study of such services can aid in understanding
the performance limitations, advise in the deployment of the monitoring system,
and help evaluate future development work. To this end, we examined the
performance of the Globus Toolkit(reg. trdmrk) Monitoring and Discovery Service
(MDS2) by instrumenting its main services using NetLogger. Our study shows a
strong advantage to caching or prefetching the data, as well as the need to
have primary components at well-connected sites.
