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Oleh Koren
Oleh Koren

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Black Friday: Would You Choose the Right Performance Test?

I recently ran a poll on LinkedIn in a Software Testing group.

Here are the results:

Spike Testing — ~55% ✅

Which means:

👉 ~45% of respondents chose the wrong answer.

And that’s not surprising.

Many engineers mix up load, volume, scalability, endurance, and spike testing — especially when the scenario sounds “real production-like”.

Let’s break it down.

What Is Spike Testing?

Spike testing is a type of performance testing where:

  • Load increases suddenly and significantly
  • System behavior is observed during the spike
  • System recovery is measured after the spike drops

It answers questions like:

  • Can the system handle a sudden traffic burst?
  • Does it crash or degrade gracefully?
  • Does it recover automatically?
  • Are there cascading failures?

Black Friday traffic jumping 4x in minutes?
That’s a textbook spike scenario.

Why It’s NOT Volume Testing

Volume testing checks how the system behaves with large amounts of data (e.g., millions of records in the database).

It’s about data size, not sudden traffic bursts.

Black Friday is not about data growth.
It’s about concurrent users arriving fast.

Why It’s NOT Endurance Testing

Endurance (soak) testing verifies system stability over long periods of sustained load.

Example:

  • 50-70% expected load
  • 6–14 hours
  • Monitoring memory leaks

Black Friday spike is short-term chaos, not long-term stability.

Why It’s Not Primarily Scalability Testing

Scalability testing evaluates how well the system scales when load increases gradually.

It checks:

  • Linear resource growth
  • Auto-scaling behavior (rules)
  • Cost efficiency

But Black Friday is not gradual.
It’s explosive.

That difference matters.

Real-World Insight

In real production systems, spike failures often happen because of:

  • Cold caches
  • Connection pool limits
  • Thread pool exhaustion
  • DB lock
  • Autoscaling delays

And here’s the critical part:

Many teams test average load.
Some test peak load.
Very few test sudden load jumps.

That’s where production incidents live.

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