Request Coalescing
Definition
Identical simultaneous requests can share an ongoing computation.
A pattern where simultaneously arriving identical requests share a common ongoing computation instead of executing it multiple times.
Simply explained
If many ask the same thing simultaneously, the work is done only once and shared.
Why it matters in practice
The term contributes to secure, maintainable, and high-performance web applications as well as resilient technical decisions.
Example from business
One hundred identical cache misses trigger only one database fetch.
Limits and pitfalls
- Merging requests with different permissions, sharing errors too long, or choosing keys too coarsely.
Origin & history
The pattern originated from cache, network, and concurrency optimization and is also known as Single Flight.
Use in mid-sized companies
- Possible application: One hundred identical cache misses trigger only one database fetch.
Frequently asked questions
What does merging identical requests mean?
A pattern where simultaneously arriving identical requests share a common ongoing computation instead of executing it multiple times. What mistakes should be avoided? Merging requests with different permissions, sharing errors too long, or choosing keys too coarsely.
Sources
Source checked on 10.10.2026. Editorial application examples are hypothetical; no evidence of real customer results.
Editorially reviewed on: