Can You Handle External Load Spikes Gracefully?¶
Type: DeepDive
Category: Performance
Audience: Engineers integrating third-party APIs, external systems, or shared infrastructure
🔍 What This Is Really About¶
When an external dependency gets slow or flakey—
what happens to your system?
- Do users get blocked?
- Do retries pile up and crush the queue?
- Does circuit breaking work as intended?
⚠️ What Can Go Wrong¶
- Synchronous dependencies cause upstream timeouts
- Retry storms triggered by brief outages
- Thread or worker pools exhausted by long-waiting calls
- Clients hammer your own API when a downstream system stalls
- Errors misclassified as timeouts or 500s → no alert
✅ Healthier Patterns¶
- Use circuit breakers with fallback responses
- Queue isolation: don’t let one downstream service monopolize capacity
- Use retries with exponential backoff and jitter
- Fast-fail logic for known high-latency paths
- Alert on change in external latency profile, not just error rate
🧠 Design Frame¶
Dependency pressure isn’t an edge case.
It’s the default condition of internet-scale systems.
❓ FAQ¶
-
Q: Can’t we just retry more?
A: Not if it breaks everything else. -
Q: Should we always fall back?
A: Only if degraded UX is better than outage.