Integrating Replication and Communication in Performance Models of
Distributed Databases

Matthias Nicola, Matthias Jarke

           Most performance studies of distributed databases model data
           replication and intersite communication only in a rudimentary
           manner. Based on an analysis of existing models, we develop
           a new 2-dimensional model of replication and link it to an
           intersite communication model that considers limited network
           capacity and load-dependent transmission delay. The resulting
           comprehensive queueing model is a balanced evaluation of both,
           the database and the communication part of a distributed
           information system, whereas previous models typically
           emphasized one and neglected the other.  This combination
           allows the analysis of mixed replication schemata which
           could not be considered in previous studies. It also allows
           the characterization of situations where the network or the
           database will be the performance bottleneck in a distributed
           information system, thus focusing tuning efforts and investment
           decisions.