This is a part of a series of posts to document my learnings after watching Udi Dahan’s Advanced Distributed Systems Design course.
Coupling is one of the fundamental concepts that affects the maintainability of software systems as discussed before. Coupling measures how dependent are the components of the system on one another.
- Incoming coupling: who depends on you (aka afferent coupling)
- Outcoming coupling: who you depend on (aka efferent coupling)
| Component | Incoming | Outgoing | Comment | Example |
|---|---|---|---|---|
| A | 5 | 0 | Called by many, does not call others; not necessarily bad | Logging library |
| B | 0 | 5 | Calls many others, not called by others; not necessarily bad | UI layer code, Controllers |
| C | 2 | 2 | Calls many others and called by many; needs investigation | Higher numbers: recipe for disaster |
| D | 0 | 0 | Does not call or get called by others | Useless code, better deleted |