System Failure and Fault Tolerance

Learn what system failure and fault tolerance are and their potential causes.


System failure in software architecture refers to a system’s inability to execute its intended functions or meet the demands of its users. Hardware faults, software failures, network failures, and human mistakes can all cause system failures.

Hardware failures

Hardware failures occur when one or more components of a system, such as a processor, memory, or storage device, stop functioning properly. Hardware failures can be caused by a variety of factors, including physical damage, wear and tear, and manufacturing defects.

As an example, assume that an e-commerce website uses a fleet of servers to handle incoming requests and process customer orders. One day, a server in the cluster fails, causing the website to become unavailable. This is a case of a hardware failure, which can happen in a critical component, such as the CPU, resulting in system failure.

Software failures

Software failures occur when one or more software programs or applications stop functioning properly. Bugs, coding errors, and compatibility issues can cause software failures.

Let’s presume that a healthcare application allows patients to schedule appointments with doctors and access their medical records online. Furthermore, assume that a software failure occurs, and patients are unable to access the application. This failure might have been caused by a recent update to the code, which could have introduced a bug that caused the application to fail.

Network failures

Network failures occur when one or more components of a network, such as routers, switches, or cables, stop functioning properly. Network failures can be caused by physical damage, configuration errors, or overloaded networks.

Consider an online gaming platform that allows players to play multiplayer games with other players around the world. A router failure (or a network failure) can cause players to experience high latency and frequent disconnections from the game servers.

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