  We represent a computer cluster as a multi-server queue with some arbitrary
bipartite graph of compatibilities between jobs and servers. Each server
processes its jobs sequentially in FCFS order. The service rate of a job at any
given time is the sum of the service rates of all servers processing this job.
We show that the corresponding queue is quasi-reversible and use this property
to design a scheduling algorithm achieving balanced fair sharing of the service
capacity.
