PAQ: Persistent Adaptive Query Middleware for Dynamic Environments

Abstract. Pervasive computing applications often entail continuous monitoring tasks, issuing persistent queries that return continuously updated views of the operational environment. We present PAQ, a middleware that supports applications’ needs by approximating a persistent query as a sequence of one-time queries. PAQ introduces an integration stratraction that allows composition of one-time query responses into streams representing sophisticated spatio-temporal phenomena of interest. A distinguishing feature of our middleware is the realization that the suitability of a persistent query’s result is a function of the application’s tolerance for accuracy weighed against the associated overhead costs. In PAQ, programmers can specify an inquiry strategy that dictates how information is gathered. Since network dynamics impact the suitability of a particular inquiry strategy, PAQ associates an introspection strategy with a persistent query, that evaluates the quality of the query’s...

• Type: Conference
• Year: 2009
• Where: MIDDLEWARE
• Authors: Vasanth Rajamani, Christine Julien, Jamie Payton, Gruia-Catalin Roman
• Keywords: Distributed And Parallel Computing, MIDDLEWARE 2009, One-time Query Responses, Paq’s Simple Api, Persistent Query