Optimization of Java Virtual Machine Flags using Feature Model and Genetic Algorithm

Optimizing the Java Virtual Machine (JVM) options in order to get the best performance out of a program for production is a challenging and time-consuming task. HotSpot, the Oracle's open-source Java VM implementation offers more than 500 options, called flags, that can be used to tune the JVM's compiler, garbage collector (GC), heap size and much more. In addition to being numerous, these flags are sometimes poorly documented and create a need of benchmarking to ensure that the flags and their associated values deliver the best performance and stability for a particular program to execute. Auto-tuning approaches have already been proposed in order to mitigate this burden. However, in spite of increasingly sophisticated search techniques allowing for powerful optimizations, these approaches take little account of the underlying complexities of JVM flags. Indeed, dependencies and incompatibilities between flags are non-trivial to express, which if not taken into account may lead to invalid or spurious flag configurations that should not be considered by the auto-tuner. In this paper, we propose a novel model, inspired by the feature model used in Software Product Line, which takes the complexity of JVM's flags into account. We then demonstrate the usefulness of this model, using it as an input of a Genetic Algorithm (GA) to optimize the execution times of DaCapo Benchmarks.