Understanding and discovering software configuration dependencies in cloud and datacenter systems

Abstract

A large percentage of real-world software configuration issues, such as misconfigurations, involve multiple interdependent configuration parameters. However, existing techniques and tools either do not consider dependencies among configuration parameters-termed configuration dependencies-or rely on one or two dependency types and code patterns as input. Without rigorous understanding of configuration dependencies, it is hard to deal with many resulting configuration issues.This thesis presents our study of software configuration dependencies in 16 widely-used cloud and datacenter systems, including dependencies within and across software components. To understand types of configuration dependencies, we conduct an exhaustive search of descriptions in structured configuration metadata and unstructured user manuals. We find and manually analyze 521 configuration dependencies. We define five types of configuration dependencies and identify their common code patterns. We report on consequences of not satisfying these dependencies and current software engineering practices for handling the consequences.We mechanize the knowledge gained from our study in a tool, cDep, which detects configuration dependencies. cDep automatically discovers five types of configuration dependencies from bytecode using static program analysis. We apply cDep to the eight Java and Scala software systems in our manual study. cDep finds 87.9% (275/313) of the related subset of dependencies from our study. cDep also finds 448 previously undocumented dependencies, with a 6.0% average false positive rate. Overall, our results show that configuration dependencies are more prevalent and diverse than previously reported and should henceforth be considered a first-class issue in software configuration engineering.

Characterizing and Detecting Configuration Compatibility Issues in Android Apps

“…However, the existing techniques [6], [8], [10], [11] analyze configuration APIs by conducting path-insensitive analysis, which can be somewhat inaccurate and miss incompatible configuration APIs without considering the if-conditions (e.g., Line 6 in Figure 2). Therefore, a path-sensitive analysis is necessary to obtain {A, X , F} by solving path constraints triggering configuration APIs with the constraint solver.…”

“…• Baseline II: ORPLOCATOR [10], the state-of-the-art technique for extracting attributes in a software system by conducting path-insensitive analysis on its configuration APIs. We ran ORPLOCATOR at different API levels to extract detection rules for unavailable attribute A at API level L. • Baseline III: CDEP [11], the state-of-the-art software misconfiguration tool which focuses on analyzing attribute dependencies in the software system. We ran CDEP among API levels to generate detection rules for the unavailable dependencies between two attributes A 1 and A 2 at API level L.…”

“…Dong et al [10] proposed ORPLO-CATOR to detect inconsistencies between documentations and configuration attributes in system code. Recently, Chen et al [11] proposed CDEP to extract attribute dependencies from source code. Although these approaches can be adapted to detect compatibility issues across multiple system versions, the proposed path-insensitive analyses are ineffective for the Android framework.…”

ConfInLog: Leveraging Software Logs to Infer Configuration Constraints

“…Prior work [13], [15], [18], [21] proposes static analysis approaches to infer configuration constraints from source code. SPEX [18] searches code patterns for different predefined constraints types, such as data range and value relationship.…”

“…For instance, the value range (0∼32767) of configuration option "LimitRequestFields" in Apache Httpd [19] is a legacy mistake in documentation [20] . In order to help users understand the configuration constraints, there are prior methods [13], [18], [21] focusing on inferring configuration constraints from software source code. The existing methods typically have two main steps.…”