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Load Testing Blog

Angular: How to use Virtual Scroll with a Flat Tree?

While developing OctoPerf's frontend I quickly stumbled upon performance issues with Angular Material tree when too many nodes where opened. OctoPerf is a load testing solution. As such, it displays a tree of actions and containers used to script the load testing scenarios:

Actions tree

With hundreds of directories expanded, the frontend quickly became slow to the point of being unusable. By default, even nodes outside of the visible part of the tree are rendered in the DOM. Since this feature is not directly available yet, I had to switch from a classic CSS scrollbar to a Virtual Scroll manually. This blog post lists all the steps I had to follow in order to use a Virtual Scroll on a complex Material Tree.


The actions tree in octoPerf uses a FlatTreeControl to manage the data. It is probably quite harder (or even impossible) to use a Virtual Scroll with a NestedTreeControl!

Modularisation in JMeter

The key to all good automation is modularisation which is effectively isolating small chunks of your application under test into separate tests and then re-using these smaller chunks in your larger, more complicated tests. Example of good candidates for modularisation are logon and logoff as well as any other high-volume journeys through your application such as search functionality.

The rationale for this approach is that if these high volume common functional activities change you only need to make the update in a single test rather than in multiple tests. If your business functionality is only used once in a single script rather than many scripts it makes no sense to modularise it but if it is used twice, or more, then it should be considered.

Sample JMX files for this tutorial are available for download:

Analyze your load tests

OctoPerf's report engine provides many graphs to sort and presents test metrics in a comprehensive way. We've tried to improve it over the years so that you can access critical information very quickly. But requirements vary from one project to the other.

In this post we will look at how you can configure the report to show your preferred metrics, and also all the shortcuts you can take to achieve this goal.

The best example is the Report summary, it allows you to navigate between all the items in a few clicks:


Importing Postman requests to Octoperf

You may have spent a considerable amount of time configuring Postman requests for your in-house API tests, and you wish to use them without having to create them again from scratch on Octoperf.

That's one of the many situations where Octoperf's compatibility with Jmeter is going to come in a handy.


A new and faster way to import Postman Collections has been implemented in Octoperf.

You can find more information here.

Postman to Jmeter

The first step will be to convert your requests into a JMeter-friendly format, using Postman Code Generation Snippet :


Load Profiles in Performance Testing

When we think of performance testing we normally think of thousands of requests with thousands of users generating huge volumes on our application under test or increasing the load until the application under test fails or runs out of resources.

This is not a good approach when determining load for your performance tests for several reasons and can in some cases render your performance testing meaningless.

This post will outline some of the pitfalls that are commonly made when it comes to generating load and will look at ways to suggest improvements to your approach to load profiles.