Many real-time decision support and sensing applications
can be expressed as continuous stream queries over
time-varying data streams, following a data stream management
model. We consider the problem of the efficient and resilient
execution of continuous stream queries in tactical edge networks
formed from mobile ad-hoc networks (MANETs) with
limited backend connectivity. Previous approaches for distributed
stream query execution target data center environments in which
networks are static, and centralized control is feasible. The
distributed, bandwidth-constrained and highly dynamic nature
of MANETs render such approaches insufficient—while a stream
query executes in a MANET, changes in the network topology
mean that any fixed query plan eventually becomes outdated.
We introduce an adaptive, network-aware approach for stream
query planning in MANETs, which supports both single- and
multi-input windowed stream query operators. The basic idea is
to increase the path diversity available when executing stream
queries by replicating query operators across many nodes in the
MANET. During execution, it becomes possible to dynamically
switch between different operator replicas based on connectivity
and other network path conditions. We evaluate our approach in
emulated MANETs, showing that it can increase substantially the
robustness of distributed stream query processing under mobility.