What are the most common anti-patterns in distributed systems?

1 Tight coupling

Tight coupling is an anti-pattern that occurs when the components of a distributed system are too dependent on each other, such that a change or failure in one component affects the others. Tight coupling reduces modularity, reusability, and testability, and increases the risk of cascading failures and inconsistent states. To avoid tight coupling, you should design your distributed system with loose coupling, which means that the components are independent, communicate through well-defined interfaces, and have minimal knowledge of each other. Loose coupling enables better separation of concerns, easier maintenance, and higher resilience.

3 Inconsistent data

Inconsistent data is an anti-pattern that occurs when the data stored or processed by a distributed system is not coherent, accurate, or up-to-date across different nodes or services. Inconsistent data can result from concurrent updates, network delays, replication lag, caching, or partial failures. Inconsistent data can affect the correctness, integrity, and quality of a distributed system, and lead to erroneous results, data loss, or corruption. To avoid inconsistent data, you should design your distributed system with consistency models, which define the rules and guarantees for how data is synchronized and accessed across the system. Depending on your requirements, you can choose between strong consistency, which ensures that all nodes see the same data at all times, or eventual consistency, which allows for temporary divergence but ensures that all nodes converge to the same data eventually.

4 Unbounded latency

Unbounded latency is an anti-pattern that occurs when the response time of a distributed system is unpredictable, variable, or too long. Unbounded latency can be caused by network congestion, resource contention, inefficient algorithms, or faulty components. Unbounded latency can degrade the performance, usability, and user experience of a distributed system, and cause timeouts, errors, or failures. To avoid unbounded latency, you should design your distributed system with latency bounds, which specify the maximum acceptable delay for each operation or request. You should also monitor, measure, and optimize the latency of your system, and use techniques such as batching, caching, parallelism, or streaming to reduce it.

5 Complex coordination

Complex coordination is an anti-pattern that occurs when the components of a distributed system need to synchronize, agree, or cooperate on some state or action, but the coordination logic is too complicated, costly, or error-prone. Complex coordination can arise from concurrency, consistency, ordering, or consensus issues, and can introduce overhead, latency, or inconsistency to a distributed system. Complex coordination can also make the system harder to understand, test, and debug. To avoid complex coordination, you should design your distributed system with simple coordination, which means that you minimize the need for coordination, use well-established protocols or algorithms, and isolate or abstract the coordination logic from the business logic.

6 Monolithic architecture

Monolithic architecture is an anti-pattern that occurs when a distributed system is built as a single, large, and cohesive unit, rather than as a collection of smaller, independent, and loosely coupled services. Monolithic architecture can limit the scalability, flexibility, and maintainability of a distributed system, and increase the complexity, coupling, and deployment frequency. Monolithic architecture can also make the system more vulnerable to failures, bottlenecks, or security breaches. To avoid monolithic architecture, you should design your distributed system with microservices architecture, which means that you decompose your system into fine-grained, modular, and self-contained services that communicate through lightweight protocols and have clear boundaries and responsibilities.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?