A Qualitative Study of Application-level Caching

TL;DR

This study investigates how developers implement application-level caching in web applications, revealing challenges and providing guidelines and patterns to improve design, implementation, and maintenance for better performance and scalability.

Contribution

It offers a qualitative analysis of developer practices in caching, deriving practical guidelines and patterns to assist in designing and maintaining application-level caching.

Findings

Developers face challenges in manual caching implementation.

Guidelines and patterns help improve caching practices.

Caching is crucial for scalability and performance.

Abstract

Latency and cost of Internet-based services are encouraging the use of application-level caching to continue satisfying users' demands, and improve the scalability and availability of origin servers. Despite its popularity, this level of caching involves the manual implementation by developers and is typically addressed in an ad-hoc way, given that it depends on specific details of the application. As a result, application-level caching is a time-consuming and error-prone task, becoming a common source of bugs. Furthermore, it forces application developers to reason about a crosscutting concern, which is unrelated to the application business logic. In this paper, we present the results of a qualitative study of how developers handle caching logic in their web applications, which involved the investigation of ten software projects with different characteristics. The study we designed is based on comparative and interactive principles of grounded theory, and the analysis of our data allowed us to extract and understand how developers address cache-related concerns to improve performance and scalability of their web applications. Based on our analysis, we derived guidelines and patterns, which guide developers while designing, implementing and maintaining application-level caching, thus supporting developers in this challenging task that is crucial for enterprise web applications.