Erlang State Machine Testing: Modeling the Circuit Breaker

Building resilient distributed systems requires software that can gracefully handle failures. The circuit breaker pattern is a fundamental tool for isolating faults, but verifying its behavior under complex state transitions requires robust testing methodologies. This text-based course guides you through modeling and verifying a circuit breaker in Erlang using property-based testing and state machines. You will transition from understanding basic state machine theory to writing custom generators and state transitions that find edge cases automatically. By the end of this course, you will be able to confidently verify the resilience of your concurrent Erlang applications. What you'll learn: - Understand the foundational concepts of the circuit breaker pattern and state machine theory in Erlang. - Model complex state transitions, including Closed, Open, and Half-Open states, using state machine testing frameworks. - Write custom generators to produce realistic sequences of commands and inputs for property-based tests. - Define state machine properties to automatically verify system behavior against expected specifications. - Analyze test failures and shrink failing test cases to isolate root causes in concurrent systems. - Apply modern property-based testing workflows to build more reliable, self-healing software. The course begins with core definitions and architectural concepts of circuit breakers and state machines. You will then progress through step-by-step written explanations to implement state transitions, configure generators, and run property-based tests to uncover hidden bugs. This course is designed for backend developers and software engineers looking to learn property-based testing in Erlang. No prior experience with state machine modeling is required, though a basic familiarity with Erlang syntax is recommended. Start reading today to master resilient system design with Erlang state machines.