{'fraction_non_alphanumeric': 0.016314199395770394, 'fraction_numerical': 0.0, 'mean_word_length': 5.8429752066115705, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A model-based distributed continuous quality assurance process to enhance the quality of service of evolving performance-intensive software systems

Time and resource constraints often force developers of highly configurable systems, such as that found in performance-intensive software, to assess their system’s performance on very few configurations and to extrapolate from these to the entire configuration space, which allows many performance bottlenecks and sources of QoS degradation to escape detection until systems are fielded. To improve the assessment of performance across large configuration spaces, we present a model-based approach to developing and deploying a new distributed continuous quality assurance (DCQA) process. Our approach builds upon and extends the Skoll environment, which is developing and validating novel software QA processes and tools that leverage the extensive computing resources of worldwide user communities in a distributed, continuous manner to significantly and rapidly improve software quality. This paper describes how our new DCQA performance assessment process enables developers to run formally-designed screening experiments that isolate the most significant options. After that, exhaustive experiments (on the now much smaller configuration space) are conducted. We implemented this process using model-based software tools and executed it in the Skoll environment to demonstrate its effectiveness via two experiments on widely used QoS-enabled middleware. Our results show that model-based DCQA processes improves developer insight into the effect of system changes on performance at an acceptable cost.