Dynamic Event-Based Runtime Monitoring of Real-Time and Contextual Properties

Abstract

Abstract. Given the intractability of exhaustively verifying software, the use of runtime-verification, to verify single execution paths at runtime, is becoming popular. Although the use of runtime verification is increasing in industrial settings, various challenges still are to be faced to enable it to spread further. We present dynamic communicating automata with timers and events to describe properties of systems, implemented in Larva, an event-based runtime verification tool for monitoring temporal and contextual properties of Java programs. The combination of timers with dynamic automata enables the straightforward expression of various properties, including replication of properties, as illustrated in the use of Larva for the runtime monitoring of a real life case studyan online transaction system for credit card. The features of Larva are also benchmarked and compared to a number of other runtime verification tools, to assess their respective strengths in property expressivity and overheads induced through monitoring.

Runtime Monitoring for Concurrent Systems

“…Many specification-based runtime-monitoring frameworks have been proposed, including four approaches to parametric monitoring: an automaton-based approach [5,7,15,16,18,20,28,34]; a regular expression-and grammar-based approach [1,18,24]; an approach based on temporal logic [6, 8, 9, 18-20, 24, 32, 33, 39, 48-50]; and a rule-based approach [4,6,35].…”

“…polyLarva [17] is an extension of LARVA [15,16] designed for distributed systems, by which a user can control the location of verifiers in the distributed system explicitly. LARVA specifies the properties of monitored systems by sets of automata which can communicate each other through channels.…”

LarvaStat: Monitoring of Statistical Properties

“…At each such position, (starting with value 0 ) is updated to u( ), with the result being output as an event: out(u( )). Formal definitions of trace semantics of event triggering are given in [2]. See Fig.…”

“…However, system executions are also rich in information related to non-functional system properties, such as system security, dependability and performance. LarvaStat extends the runtime verification tool L ÖÚ [2] with the capability of collecting statistical information, and verifying non-functional requirements based on such statistics. Taking security as an example application area, LarvaStat allows for the characterisation of suspicious user behaviour through statistical evaluation, which can subsequently be used to blacklist users deemed suspicious.…”

Safe Runtime Verification of Real-Time Properties

“…Although the specification written in terms counterexample traces lacks the readability of one written in full DC, it has the distinct advantage of being automatically implementable as a runtime monitor. It is well known how to translate such formulae into phase event automata (PEAs) [9], which we use, in turn, to produce dynamic automata with timers and events (DATEs) which we have used for runtime verification of real-time properties [6], and are implemented in the tool Larva. The tool implements a transformation from PEAs to DATEs which has been proved to be sound and complete.…”