Difference between load and spike testing

Question

How is a load test different from a Spike test, Considering the below scenarios.

Load test: Using an automation tool(JMeter in my case) I create a load of 1000 virtual users loaded in 1 sec(ramp up period).

Spike test: Using an automation tool(JMeter in my case) I create a continuous load of 400 virtual users loaded every 1 sec and a spike load of 600 virtual users loaded in 1 sec at a certain point in time.

When there is a spike load induced is it not the same as a load test described?

So my point is what is the need of a spike test if load tests can be carried out continuously at varied load conditions?

Test scenario: Application tested : Website. Automation tool : Jmeter. Speed of internet used while testing: 3 MBPS.

I`m thanking you all in advance.

Answer 1

According to "Performance Testing Guidance for Web Applications", "spike testis a type of performance test focused on determining or validating performance characteristics of the product under test when subjected to workload models and load volumes that repeatedly increase beyond anticipated production operations for short periods of time.". So I think about analogy with Geometric or Algebraic progression, because volumes are repeatedly (and rapidly) increased. Also this and other definitions are paying attention to short period of time.

Load testing is more general term, without specified time (short or long) of testing or pattern to increase load volumes.

Answer 2

Load Testing: It helps us to know how much load a application/System can bear at a point of time.

        Ex: Let a normal man can drink Maximum 3lt water at a time.

spike testing: It helps us to know the behaviour of a system by giving suddenly high amount of load.

        Ex: For spike testing we try to know whether a normal man can drink 4lt or more at a time?  

Answer 3

A spike test is a kind of load test, used to simulate bursty traffic patterns.

For example, you might want to support 1 million client requests an hour. That's an average of 277 requests/sec. However, that doesn't account for varying usage patterns, like a sudden burst of traffic followed by a lull period. A spike test would simulate these bursts, where the short-term request rate can be much higher or lower than the expected average.