What is distributed systems observability and what challenges does it introduce compared to monolith observability?

Distributed systems observability refers to the ability to understand the internal state and behavior of a system that consists of multiple independently deployed services communicating over a network. Unlike a monolith — where all code runs in one process and profiling, logging, and debugging are straightforward — distributed systems introduce fundamental challenges that require purpose-built tooling.

Challenge 1 — No single log stream: A request touches 10 services; their logs are in 10 different places. Log correlation requires shared request IDs injected into every service's logs. Without structured logging and log aggregation, tracing a request manually is infeasible.

Challenge 2 — Partial failures: In a monolith, a failure either crashes the process or it does not. In distributed systems, Service A can respond successfully while Service B, called internally by A, silently times out and returns a degraded result. These partial failures are invisible without distributed tracing and upstream error propagation.

Challenge 3 — Clock skew: Services run on different machines with clocks that drift. Log timestamps from different services cannot be naively sorted — a span ending at 10:00:00.001 on Service B might be recorded before a span starting at 10:00:00.000 on Service A due to clock drift. OpenTelemetry uses monotonic clocks within a single process and accepts some clock-skew inaccuracy across processes.

Challenge 4 — Attribution: When latency spikes, which of the 10 services caused it? Without traces linking spans causally, you are guessing. Distributed tracing was invented specifically to solve attribution in distributed systems.

Invest now in Acorns!!! 🚀
Join Acorns and get your $5 bonus!

Acorns is a micro-investing app that automatically invests your "spare change" from daily purchases into diversified, expert-built portfolios of ETFs. It is designed for beginners, allowing you to start investing with as little as $5. The service automates saving and investing. Disclosure: I may receive a referral bonus.

Invest now!!! Get Free equity stock (US, UK only)!

Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.

The Robinhood app makes it easy to trade stocks, crypto and more.

Webull! Receive free stock by signing up using the link: Webull signup.