Distributed Tracing

Distributed Tracing Overview

At its core, distributed tracing is about doing one thing well inside your single-spa project. Once you understand the pattern, you can apply it consistently across features and teams.

Good distributed tracing pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

import { registerApplication, start } from 'single-spa';

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});

start();

single-spa orchestrates multiple framework apps on one page through a root config.

Distributed Tracing Example

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});
start();

• Start from a minimal Distributed Tracing example and grow it only as needed.
• Keep configuration explicit so Distributed Tracing behaves the same in every environment.
• Name things clearly so teammates understand your Distributed Tracing at a glance.
• Add tests around Distributed Tracing early to lock in expected behaviour.

Single-SPA Cheatsheet

Core single-spa APIs related to distributed tracing.

How Distributed Tracing Works in Single-SPA

Distributed Tracing is part of how single-spa lets multiple applications — even in different frameworks — coexist on one page. A root config registers each app and controls when it is active.

single-spa orchestrates multiple framework apps on one page through a root config.

• A root config registers apps and calls start().
• Each app exports bootstrap, mount, and unmount lifecycles.
• activeWhen decides which routes each app owns.
• Import maps resolve each app's bundle at runtime.

Practical Guidance for Distributed Tracing

For reliable micro frontends, distributed tracing should isolate failures and keep shared state minimal. Let each team own its app end to end while agreeing on a few shared contracts.

Common Mistakes

• Copying distributed tracing snippets without understanding what each line does.
• Skipping error handling and edge cases when wiring up distributed tracing.
• Leaving distributed tracing untested, so regressions slip into production.
• Over-engineering distributed tracing before you actually need the extra flexibility.

Key Takeaways

• Distributed Tracing is a core part of working effectively with single-spa.
• Start small and keep distributed tracing focused on a single responsibility.
• Apply consistent patterns so distributed tracing scales across your project.
• Test and document distributed tracing to keep it maintainable over time.