Applications designed for dynamic networks often require
continuous monitoring of the environment. Applications
acquire information by issuing persistent queries that
return continuously updated views of the operational environment.
In reality, it is not feasible to provide an exact
reflection under dynamic conditions. We present a framework
for expressing persistent queries as sequences of onetime
queries. We allow a persistent query to include an inquiry
strategy that controls how the associated component
queries are issued and and integration strategy that defines
a mechanism to combine the component queries’ results.
Since the dynamics of the network can impact the suitability
of the strategies used, we associate an introspection strategy
with any persistent query, which uses information about the
persistent query’s execution to evaluate the quality of the
returned results. Using introspection, an application can
adapt the way that the persistent query is issued. With this
framework, applications can exercise a new degree of semantic
control over the results of a persistent query.
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