When hungry, feed is the norm. But if you feel hungry frequently, does it mean that you have to feed more? Well, there may be a real problem in the system and I think we need to get to root cause rather than feeding more. This is exactly what has been happening in the system performance world. When system goes slow or there are errors in accessing the system, normally, the tendency is to add additional hardware rather than getting to the root cause.

1. The moving target - Performance
Testing / Engineering in real world
When hungry, feed is the norm. But if you feel hungry frequently, does it mean
that you have to feed more? Well, there may be a real problem in the system and
I think we need to get to root cause rather than feeding more.
This is exactly what has been happening in the system performance world. When
system goes slow or there are errors in accessing the system, normally, the
tendency is to add additional hardware rather than getting to the root cause.
So, lets look at what is performance testing?
Many would answer that it is performed to determine and measure the system
performance in a given workload condition.

2. Well… That is correct but!!!!
To answer BUT, lets look at what is a system today?
System today consists of various sub systems, which interact, integrate and work
together.
Lets take an example, I have an e-commerce application available on my mobile
to shop and the same is available on web browser as well. Tomorrow, it will be
available on TV and additional devices.
These systems are interacting with various other systems on backend such as
store management, warehouse management, delivery management, finance
management, payment gateways and more.
So what happens now?
Usually, the e-commerce company engages with a team of performance testers to
understand if the system can handle load in certain conditions.
There are 2 working conditions to any of the applications:
1. The best scenario which actually may not the best for the e-commerce
company – Usual load conditions
2. The worst scenario which may be the best for the e-commerce company –
Heavy load condition or spike in load
They get a set of performance reports, which provides information of system
behaviour under different conditions.
Well what next?
The response would normally be the front end application response time and not
other integrated server parameters and if the response time does not meet the
SLA criteria set, the normal recommendation would be to throw more hardware
to the problem. Customers sometime go overboard in adding additional

3. hardware which costs. This can sometimes solve the problem but will it on a long
run?
The answer to this is NO.
What are we missing?
1. Different applications behave differently when integrated
2. Each integrated application itself needs be optimised so that it does not
add additional load to the system
3. System / OS settings itself can help solve many problems if done right
4. Database settings needs to be optimised
5. The web servers sometimes add to the problem and needs to be configured
properly
Once all the settings, configurations and optimisations are in place, we can now
answer, how much is actually right.
So, today it is not merely performance testing but performance engineering. As
part of a performance engineering engagement, an organization should be able
to help:
1. Guide customers to the problematic areas
2. Coordinate with developers, System engineering, database engineers and
vendors to provide them insights of issues which can be corrected
3. Provide customers benchmark results and inputs on hardware required in
various conditions to help them plan and budget properly
4. Help them implement the right production strategy for a long haul rather
than a short term fix