Types of Failures in Distributed Systems

This lesson classifies failures by their source and by what another component can observe. You will compare hardware faults, software defects and communication problems, then choose detection and recovery methods for a checkout service. The same symptom can have several causes, so keep observations separate from diagnoses.

Building a large-scale application on a single, powerful machine is inherently fragile.

If the only serving machine fails, the service loses that serving path. Additional machines can reduce that risk, but only if their failure domains and dependencies are sufficiently independent. A shared power source, configuration error or overloaded database can affect many replicas at once.

Understanding these failure modes is a critical skill for any engineer and a frequent focus in modern System Design.

This lesson explores the inevitable failures in distributed systems, categorizing them to help you design resilient and robust architectures. Common categories include hardware failures, software failures, and network failures, each of which affects system reliability in distinct ways.

The following illustration highlights failure points across different services in a distributed system.