Recently, large language models (LLMs) have shown strong potential in code generation tasks. However, there are still gaps before they can be fully applied in actual software development processes. Accurately assessing the code generation capabilities of large language models has become an important basis for evaluating and improving the models. Some existing works have constructed datasets to evaluate the capabilities of these models. However, the current evaluation process may encounter the illusion of “Specialist in Familiarity”, primarily due to three gaps: the exposure of target code, case timeliness, and dependency availability. The fundamental reason for these gaps is that the code in current datasets may have been extensively exposed and exercised during the training phase, and due to the continuous training and development of LLM, their timeliness has been severely compromised. The key to solve the problem is to, as much as possible, evaluate the LLMs using code that they have not encountered before. Thus, the fundamental idea in this paper is to draw on the concept of code obfuscation, changing code at different levels while ensuring the functionality and output. To this end, we build a code-obfuscation based benchmark OBFusEvAL. We first collect 1,354 raw cases from five real-world projects, including function description and code. Then we use three-level strategy (symbol, structure and semantic) to obfuscate descriptions, code and context dependencies. We evaluate four LLMs on Obfu-sevaland compared the effectiveness of different obfuscation strategy. We use official test suites of these projects to evaluate the generated code. The results show that after obfuscation, the average decrease ratio of test pass rate can up to 62.5%.

Runtime misconfiguration can lead to software performance degradation and even cause failure. It is usually caused by invalid parameter values set by users. Developers typically perform sanity checks during the configuration parsing stage to prevent invalid parameter values. However, we discovered that even valid values that pass these checks can also lead to unexpected severe consequences. Our study reveals the underlying reason: the value of runtime configuration parameters may interact with other constants and variables when propagated and used, altering its original effect on software behavior. Consequently, parameter values may no longer be valid when encountering complex runtime environments and workloads. Therefore, it is extremely challenging for users to properly configure the software before it starts running. This paper presents the first comprehensive and in-depth study (to the best of our knowledge) on how configuration affects software at runtime through the interaction with constants, and variables (PCV Interaction). Parameter values represent user intentions, constants embody developer knowledge, and variables are typically defined by the runtime environment and workload. This interaction essentially illustrates how different roles jointly determine software behavior. In this regard, we studied 705 configuration parameters from 10 large-scale Software systems. We reveal that a large portion of configuration parameters interact with constants/variables after parsing. We analyzed the interaction patterns and their effects on software runtime behavior. Furthermore, we highlighted the risks of PCV interaction and identified potential issues behind specific interaction patterns. Our findings expose the “double edge” of PCV interaction, providing new insights and motivating the development of new automated techniques to help users configure software appropriately and assist developers in designing better configurations.

Software systems introduce an increasing number of configuration options to provide flexibility, and support updating the options on the fly to provide persistent services. This mechanism, however, may affect the system reliability, leading to unexpected results like software crashes or functional errors. In this paper, we refer to the bugs caused by on-the-fly configuration updates as on-the-fly configuration bugs, or OCBugs for short. In this paper, we conducted the first in-depth study on 75 real-world OCBugs from 5 widely used systems to understand the symptoms, root causes, and triggering conditions of OCBugs. Based on our study, we designed and implemented Parachute, an automated testing framework to detect OCBugs. Our key insight is that the value of one configuration option, either loaded at the startup phase or updated on the fly, should have the same effects on the target program. Parachute generates tests for on-the-fly configuration updates by mutating the existing tests and conducts differential analysis to identify OCBugs. We evaluated Parachute on 7 real-world software systems. The results show that Parachute detected 75% (42/56) of the known OCBugs, and reported 13 unknown bugs, 11 of which have been confirmed or fixed by developers until the time of writing.

NVMe SSD hugely boosts the I/O speed, with up to GB/s throughput and microsecond-level latency. Unfortunately, DBMS users can often find their high-performanced storage devices tend to deliver less-than-expected or even worse performance when compared to their traditional peers. While many works focus on proposing new DBMS designs to fully exploit NVMe SSDs, few systematically study the symptoms, root causes and possible detection methods of such performance mismatches on existing databases. In this paper, we start with an empirical study where we systematically expose and analyze the performance mismatches on six popular databases via controlled configuration tuning. From the study, we find that all six databases can suffer from performance mismatches. Moreover, we conclude that the root causes can be categorized as databases' unawareness of new storage devices characteristics in I/O size, I/O parallelism and I/O sequentiality. We report 17 mismatches to developers and 15 are confirmed. Additionally, we realize testing all configuration knobs yields low efficiency. Therefore, we propose a fast performance mismatch detection framework and evaluation shows that our framework brings two orders of magnitude speedup than baseline without sacrificing effectiveness.

Misconfigurations have drawn tremendous attention for their increasing prevalence and severity, and the main causes are the complexity of configurations as well as the lack of domain knowledge for software. To diagnose misconfigurations, one typical approach is to find out the conditions that configuration options should satisfy, which we refer to as configuration constraints. Current researches only handled part of the situations of configuration constraints in source code, which provide only limited help for misconfiguration diagnosis. To better extract configuration constraints, we conduct a comprehensive manual study on the existence and variance of the configuration constraints in source code from five pieces of popular open-source software. We summarized several findings from different aspects, including the general statistics about configuration constraints, the general features for specific configurations, and the obstacles in extraction of configuration constraints. Based on the findings, we propose several suggestions to maximize the automation of constraints extraction.

Fault-tolerance is essential in extreme-scale data processing systems. Pro-active fault-tolerance scheme (such as the speculative execution in MapReduce framework), can dramatically improve the response time of job executions when the failure becomes norm rather than an exception. Efficient pro-active fault-tolerance schemes require precise knowledge on the task executions, which has been an open challenges for decades. To well address the issue, in this paper we design and implement RiskI, a profile-based prediction algorithm in conjunction with a risk-aware task assignment algorithm to accelerate task executions, taking the uncertainty nature of tasks into account. Our design demonstrates that the nature uncertain not only brings great challenges but also new opportunities. With a careful design, we can benefit from such uncertainties. We implement the idea in Hadoop 0.21.0 systems and the experimental results show that compared with the traditional LATE algorithm, the response time can be improved by 46% with the same system throughput.

Mobile sensors are often employed for enhancing the sensing coverage and assisting the data gathering in wireless sensor networks. Equipped with unlimited mobility, they are able to move anywhere within the monitored field. Despite the promising simulation (or testbed) result and theoretical conclusion in paper, we have to realize the assumption on unlimited mobility has limitations and is practically unrealistic in many applications.