Microservices Architecture: Building Scalable Applications

Learning Objectives Define a distributed system and contrast monolithic and microservices architectures. Explain the challenges of concurrency in a distributed environment, such as race conditions and deadlocks. Describe key fault tolerance patterns, including Circuit Breakers and Retries. Apply the CAP Theorem to analyze the trade-offs between Consistency, Availability, and Partition Tolerance. Design a simple, fault-tolerant interaction between two microservices. Identify common pitfalls in distributed system design, such as ignoring network latency and data consistency. Ever wonder how Netflix can stream to millions of users at once, even if one of its servers fails? 🖥️💥 That's the power of distributed systems! This chapter dives into the world of distributed syste...

TermDefinitionExample Distributed SystemA collection of independent computers that appears to its users as a single coherent system. These computers communicate and coordinate their actions by passing messages to one another.A web application with a user-facing web server, a separate database server, and a caching server. Each is a different computer, but they work together to serve the user. ConcurrencyThe ability of different parts or units of a program, algorithm, or problem to be executed out-of-order or in partial order, without affecting the final outcome.In an e-commerce app, one microservice processes a new order while another simultaneously updates the inventory count for the purchased items. Fault ToleranceThe property that enables a system to continue operating properly in the...

CAP Theorem Trade-off Choose 2 of 3: Consistency (C), Availability (A), Partition Tolerance (P). Since network partitions (P) are a fact of life in distributed systems, the real choice is between C and A. Use this during the initial design phase. If your system requires all data to be perfectly up-to-date for every user (like a bank transfer), prioritize Consistency (CP). If your system can tolerate slightly stale data to ensure it's always responsive (like a social media like count), prioritize Availability (AP). Circuit Breaker Pattern State Machine: CLOSED -> OPEN -> HALF-OPEN. Wrap a protected function call in a circuit breaker object which monitors for failures. When failures reach a threshold, the breaker trips (OPEN) and subsequent calls fail immediately. Aft...