More Like this

1. An Evolutionary Study of Configuration Design and Implementation in Cloud Systems

   https://doi.org/10.1109/ICSE43902.2021.00029  

   Zhang, Yuanliang; He, Haochen; Legunsen, Owolabi; Li, Shanshan; Dong, Wei; Xu, Tianyin (May 2021, 2021 IEEE/ACM 43rd International Conference on Software Engineering)

   null (Ed.)

   Many techniques were proposed for detecting software misconfigurations in cloud systems and for diagnosing unintended behavior caused by such misconfigurations. Detection and diagnosis are steps in the right direction: misconfigurations cause many costly failures and severe performance issues. But, we argue that continued focus on detection and diagnosis is symptomatic of a more serious problem: configuration design and implementation are not yet first-class software engineering endeavors in cloud systems. Little is known about how and why developers evolve configuration design and implementation, and the challenges that they face in doing so. This paper presents a source-code level study of the evolution of configuration design and implementation in cloud systems. Our goal is to understand the rationale and developer practices for revising initial configuration design/implementation decisions, especially in response to consequences of misconfigurations. To this end, we studied 1178 configuration-related commits from a 2.5 year version-control history of four large-scale, actively-maintained open-source cloud systems (HDFS, HBase, Spark, and Cassandra). We derive new insights into the software configuration engineering process. Our results motivate new techniques for proactively reducing misconfigurations by improving the configuration design and implementation process in cloud systems. We highlight a number of future research directions. 

   more » « less
2. Static detection of silent misconfigurations with deep interaction analysis

   https://doi.org/10.1145/3485517  

   Zhang, Jialu; Piskac, Ruzica; Zhai, Ennan; Xu, Tianyin (October 2021, Proceedings of the ACM on Programming Languages)

   The behavior of large systems is guided by their configurations: users set parameters in the configuration file to dictate which corresponding part of the system code is executed. However, it is often the case that, although some parameters are set in the configuration file, they do not influence the system runtime behavior, thus failing to meet the user’s intent. Moreover, such misconfigurations rarely lead to an error message or raising an exception. We introduce the notion of silent misconfigurations which are prohibitively hard to identify due to (1) lack of feedback and (2) complex interactions between configurations and code. This paper presents ConfigX, the first tool for the detection of silent misconfigurations. The main challenge is to understand the complex interactions between configurations and the code that they affected. Our goal is to derive a specification describing non-trivial interactions between the configuration parameters that lead to silent misconfigurations. To this end, ConfigX uses static analysis to determine which parts of the system code are associated with configuration parameters. ConfigX then infers the connections between configuration parameters by analyzing their associated code blocks. We design customized control- and data-flow analysis to derive a specification of configurations. Additionally, we conduct reachability analysis to eliminate spurious rules to reduce false positives. Upon evaluation on five real-world datasets across three widely-used systems, Apache, vsftpd, and PostgreSQL, ConfigX detected more than 2200 silent misconfigurations. We additionally conducted a user study where we ran ConfigX on misconfigurations reported on user forums by real-world users. ConfigX easily detected issues and suggested repairs for those misconfigurations. Our solutions were accepted and confirmed in the interaction with the users, who originally posted the problems. 

   more » « less
3. Test-Case Prioritization for Configuration Testing

   https://doi.org/10.1145/3460319.3464810  

   Cheng, Runxiang; Zhang, Lingming; Marinov, Darko; Xu, Tianyin (July 2021, ACM SIGSOFT International Symposium on Software Testing and Analysis)

   Configuration changes are among the dominant causes of failures of large-scale software system deployment. Given the velocity of configuration changes, typically at the scale of hundreds to thousands of times daily in modern cloud systems, checking these configuration changes is critical to prevent failures due to misconfigurations. Recent work has proposed configuration testing, Ctest, a technique that tests configuration changes together with the code that uses the changed configurations. Ctest can automatically generate a large number of ctests that can effectively detect misconfigurations, including those that are hard to detect by traditional techniques. However, running ctests can take a long time to detect misconfigurations. Inspired by traditional test-case prioritization (TCP) that aims to reorder test executions to speed up detection of regression code faults, we propose to apply TCP to reorder ctests to speed up detection of misconfigurations. We extensively evaluate a total of 84 traditional and novel ctest-specific TCP techniques. The experimental results on five widely used cloud projects demonstrate that TCP can substantially speed up misconfiguration detection. Our study provides guidelines for applying TCP to configuration testing in practice. 

   more » « less
4. Joint Bayesian estimation of cell dependence and gene associations in spatially resolved transcriptomic data

   https://doi.org/10.1038/s41598-024-60002-z  

   Chakrabarti, Arhit; Ni, Yang; Mallick, Bani K (December 2024, Scientific Reports)

   Abstract Recent technologies such asspatial transcriptomics, enable the measurement of gene expressions at the single-cell level along with the spatial locations of these cells in the tissue. Spatial clustering of the cells provides valuable insights into the understanding of the functional organization of the tissue. However, most such clustering methods involve some dimension reduction that leads to a loss of the inherent dependency structure among genes at any spatial location in the tissue. This destroys valuable insights of gene co-expression patterns apart from possibly impacting spatial clustering performance. In spatial transcriptomics, the matrix-variate gene expression data, along with spatial coordinates of the single cells, provides information on both gene expression dependencies and cell spatial dependencies through its row and column covariances. In this work, we propose a joint Bayesian approach to simultaneously estimate these gene and spatial cell correlations. These estimates provide data summaries for downstream analyses. We illustrate our method with simulations and analysis of several real spatial transcriptomic datasets. Our work elucidates gene co-expression networks as well as clear spatial clustering patterns of the cells. Furthermore, our analysis reveals that downstream spatial-differential analysis may aid in the discovery of unknown cell types from known marker genes. 

   more » « less
5. Security Misconfigurations in Open Source Kubernetes Manifests: An Empirical Study

   https://doi.org/10.1145/3579639  

   Rahman, Akond; Shamim, Shazibul Islam; Bose, Dibyendu Brinto; Pandita, Rahul (July 2023, ACM Transactions on Software Engineering and Methodology)

   Mauro Pezzè (Ed.)

   Context: Kubernetes has emerged as the de-facto tool for automated container orchestration. Business and government organizations are increasingly adopting Kubernetes for automated software deployments. Kubernetes is being used to provision applications in a wide range of domains, such as time series forecasting, edge computing, and high performance computing. Due to such a pervasive presence, Kubernetes-related security misconfigurations can cause large-scale security breaches. Thus, a systematic analysis of security misconfigurations in Kubernetes manifests, i.e., configuration files used for Kubernetes, can help practitioners secure their Kubernetes clusters. Objective: The goal of this paper is to help practitioners secure their Kubernetes clusters by identifying security misconfigurations that occur in Kubernetes manifests . Methodology: We conduct an empirical study with 2,039 Kubernetes manifests mined from 92 open-source software repositories to systematically characterize security misconfigurations in Kubernetes manifests. We also construct a static analysis tool called Security Linter for Kubernetes Manifests (SLI-KUBE) to quantify the frequency of the identified security misconfigurations. Results: In all, we identify 11 categories of security misconfigurations, such as absent resource limit, absent securityContext, and activation of hostIPC. Specifically, we identify 1,051 security misconfigurations in 2,039 manifests. We also observe the identified security misconfigurations affect entities that perform mesh-related load balancing, as well as provision pods and stateful applications. Furthermore, practitioners agreed to fix 60% of 10 misconfigurations reported by us. Conclusion: Our empirical study shows Kubernetes manifests to include security misconfigurations, which necessitates security-focused code reviews and application of static analysis when Kubernetes manifests are developed. 

   more » « less