Thesis: Concurrent Programming for Scalable Web Architectures

Benjamin Erb (@b_erb) from Ulm University recently published his diploma thesis on "Concurrent Programming for Scalable Web Architectures". The thesis provides a comprehensive survey on different concepts and techniques of concurrency inside web  architectures, including web servers, application logic and storage backends. It incorporates research publications, hands-on reports  and also regards popular programming languages, frameworks and  databases.

Abstract:

Web architectures are an important asset for various large-scale web applications, such as social networks or e-commerce sites. Being able to handle huge numbers of users concurrently is essential, thus scalability is one of the most important features of these architectures. Multi-core processors, highly distributed backend architectures and new web technologies force us to reconsider approaches for concurrent programming in order to implement web applications and fulfil scalability demands. While focusing on different stages of scalable web architectures, we provide a survey of competing concurrency approaches and point to their adequate usages.

Topics include:

• Fundamentals of Concurrency, Scalability and Web Architectures
• Architectural Model for Scalabale Web Infrastructures
• Web Server Architectures (e.g. multithreaded, event-driven and hybrid architectures)
• Concurrency Concepts for Applications and Business Logic (including threads, actors, software transactional memory and event-driven systems)
• Concurrent and Scalable Storage Backends (consistency models, internals, systems)
• Recommendations of appropriate mechanisms, concepts and architectures
• General discussion on the challenges of concurrent and distributed programming
• Outlook on upcoming trends in programming languages and web architectures

Table of Contents:

• 1. Introduction
  • 1.1 Motivation
  • 1.2 Scope of this Thesis
  • 1.3 Methodulogy of the Study
  • 1.4 Road Map
• 2. The World Wide Web, Concurrency and Scalability
  • 2.1 The World Wide Web
  • 2.2 Web Applications
  • 2.3 Concurrency
  • 2.4 Scalability
  • 2.5 Summary
• 3. The Quest for Scalable Web Architectures
  • 3.1 Traditional Web Architectures
  • 3.2 Cloud Architectures
  • 3.3 An Architectural Model for Scalabale Web Infrastructures
  • 3.4 Scaling Web Applications
  • 3.5 Summary
• 4. Web Server Architectures for High Concurrency
• 4.1 Overview
• 4.2 Server Architectures
• 4.3 The Case of Threads vs. Events
• 4.4 Summary
• 5. Concurrency Concepts for Applications and Business Logic
  • 5.1 Overview
  • 5.2 Concurrency Based on Threads, Locks and Shared State
  • 5.3 Concurrency via Software Transactional Memory
  • 5.4 Actor-based Concurrency
  • 5.5 Event-driven Concurrency
  • 5.6 Other Approaches and Concurrency Primitives
  • 5.7 Summary
• 6. Concurrent and Scalable Storage Backends
  • 6.1 The Challenge of Distributed Database Systems
  • 6.2 Internals of Distributed Database Systems
  • 6.3 Types of Distributed Database Systems
  • 6.4 Summary
• 7. Recommendations
  • 7.1 Selecting a Web Server Architecture
  • 7.2 Picking the Right Concurrency Concepts for Application Logic
  • 7.3 Choosing a Storage Backend
  • 7.4 Summary
• 8. Discussion
• 9. Outlook
  • 9.1 Emerging Web Architecture Trends
  • 9.2 Trends in Programming Languages
  • 9.3 Summary
• 10. Conclusion