Abstract
The design space for large, multipath datacenter networks is
large and complex, and no one design fits all purposes. Network
architects must trade off many criteria to design costeffective,
reliable, and maintainable networks, and typically
cannot explore much of the design space. We present Condor,
our approach to enabling a rapid, efficient design cycle.
Condor allows architects to express their requirements as constraints
via a Topology Description Language (TDL), rather
than having to directly specify network structures. Condor
then uses constraint-based synthesis to rapidly generate candidate
topologies, which can be analyzed against multiple
criteria. We show that TDL supports concise descriptions
of topologies such as fat-trees, BCube, and DCell; that we
can generate known and novel variants of fat-trees with simple
changes to a TDL file; and that we can synthesize large
topologies in tens of seconds. We also show that Condor
supports the daunting task of designing multi-phase network
expansions that can be carried out on live networks.