Scatter-Gather Aggregator¶
Query independent branches in parallel and combine enough answers under one deadline.
flowchart LR
J[Junior: why fan out] --> M[Middle: how gather works] --> S[Senior: tail failures] --> P[Professional: scale and admission]
flowchart LR
Request --> A[Shard A] --> Merge
Request --> B[Shard B] --> Merge
| Level | Guide | You are done when |
|---|---|---|
| Junior | Definition and why | You can explain tail amplification. |
| Middle | How it works | You can choose all-of-n, k-of-n, or best effort. |
| Senior | Failures and mistakes | You can bound hedging and partial failure. |
| Professional | Best practices and scale | You can budget latency and fleet load. |
Practice rule: Bound fan-out and propagate one end-to-end deadline.