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Load-Testing

Open source Load Testing tools comparative study

Summary

Different open-source load-testing tools report response times in very different ways, and default settings can drastically affect results. A single test scenario was executed with JMeter, Locust, Gatling, and K6 using identical load, connection reuse disabled and a shared target URL. The study shows major discrepancies across tools due to differences in TCP/TLS handling, connection pooling, DNS resolution, and timing definitions.

JMeter and Gatling report values close to browser timings, while Locust reports significantly higher numbers and K6 under-reports unless metrics are combined. Understanding how each tool measures response time is essential before comparing results or drawing performance conclusions. The key takeaway: trust results only when you know exactly what the tool is measuring and how its configuration impacts the load.

Table of Contents

Performance Testing in Production

In this Blog Post we are going to discuss performance testing in production.

Now before you think we have gone mad and lost our minds completely this is not as crazy as it sounds.

Production is an environment that:

  • Is sized accurately,
  • Has a suitable diversity of data,
  • Has the correct data volumes,
  • Is on the correct infrastructure.

All the things you spend a significant amount of time getting right in your performance testing environment and that can be difficult to achieve.

Performance Testing for large scale programmes

In this post we are going to look at performance testing on large scale programmes.

A few the posts we write define techniques and approaches based on a single application under test but sometimes you are faced with the prospect of performance testing:

  • A new solution that replaces several legacy applications,
  • A service migration from once cloud provider to another or one data center to another,
  • An infrastructure update that covers multiple applications or services,
  • A new solution that compliments and integrates with existing software.

Now, especially in the case of migration of services, performance is key, and you cannot afford to see a degradation in performance as the business users will have already become accustomed to the software and how it performs.

You can look to make it perform better but it is unlikely they will tolerate poorer performance just because you have migrated from one platform to another.

Equally, new solutions that replace legacy application will (rightly or not) be expected to perform better than their predecessor which is a challenge as your new solution will undoubtedly have a different workflow and approach to delivering what the end-users want.

These types of large-scale programmes can on the surface seem complex from a Quality Assurance perspective and we have put together this guide to help you understand some of the techniques you can use to ensure that the performance testing aspect of the testing is manageable and not overwhelming. We have set out in the sections below things to consider to assist in the performance testing of large-scale programmes of work.

Performance Testing in application Design

There are many articles on the huge benefits of performance testing integrated into the development process and the concept of shift-left performance testing.

We have also discussed the concepts of Load Test Driven Development which involves the creation of performance testing in parallel with the code development and sits alongside Test Driven Development.

We are going to consider in this post how involving performance testing resources in the application design process can be a benefit.

Load Test Driven Development

We are going to explore whether Load Test Driven Development is an idea that would be worth pursuing for your organisation.

We will recap on what Test-Driven Development (TDD) is in the next section but fundamentally

Test-Driven Development is a philosophy and practice that involves building and executing tests before implementing the code or a component of a system

Now when you think about this, does it make sense to try and run a performance test before we have developed any code?

We think it does and we are going to explain why. For clarity we are not suggesting that Load test Driven Development should replace TDD but rather to compliment it.