Quantified Event Automata: Towards Expressive and Efficient Runtime Monitors

Abstract

Abstract. Runtime verification is the process of checking a property on a trace of events produced by the execution of a computational system. Runtime verification techniques have recently focused on parametric specifications where events take data values as parameters. These techniques exist on a spectrum inhabited by both efficient and expressive techniques. These characteristics are usually shown to be conflicting -in state-of-the-art solutions, efficiency is obtained at the cost of loss of expressiveness and vice-versa. To seek a solution to this conflict we explore a new point on the spectrum by defining an alternative runtime verification approach. We introduce a new formalism for concisely capturing expressive specifications with parameters. Our technique is more expressive than the currently most efficient techniques while at the same time allowing for optimizations.

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].…”

“…We show that CSP E can neatly describe a system of Unix-like processes and file descriptors. We also implement a domain-specific language (DSL) based on CSP E and compare its performance with quantified event automata (QEA) [5,36,46,45] implemented in [14], using a simulated event log of the Unix-like processes and file descriptors. QEA is an automata-based monitoring framework, which, according to [38], is one of the most expressive of this kind.…”

“…In this section, we introduce CSP E using a motivating example, and we compare it to QEA [5,36,46,45]. We argue that CSP E excels at describing properties that are composed of local properties (i.e., to a process) yet interact globally.…”

Comprehension of Spacecraft Telemetry Using Hierarchical Specifications of Behavior

“…These systems support various formalisms, such as state machines [14,19,11,7,5], regular expressions [4,19], variations over the µ-calculus [6], temporal logics [6,19,7,15,9,10,12], grammars [19], and rulebased systems [8,17]. Some of these systems focus on being efficient.…”

“…Some of these systems focus on being efficient. However, this efficiency is typically achieved at the price of some lack of expressiveness, as discussed in [5]. Our previous research has focused on more expressive formalisms, including rule-based systems, such as Ruler [8] and more recently LogFire [17].…”