Unifying percentile displays in Locust's statistics screens

[FooQoo]

Prerequisites

• I am using the latest version of Locust
• I am suggesting a new feature, not asking a question

Description

Summary

I have noticed a lack of consistency in the percentile displays on Locust's UI statistical screens. Specifically, there is a discrepancy in the percentiles displayed between the overall statistics screen (statics) and the screen that records the time series change of statistics (charts).

Current Display

• Statics screen: Median/90%ile/99%ile
• Charts screen: Median/95%ile

Proposed Changes

To achieve a more consistent data analysis experience, I propose the following changes:

1. Add 95%ile to the Statics screen.
2. Add 90%ile and 99%ile to the Charts screen.

These changes will unify the percentile displays across both screens, making it easier for users to compare data between different screens.

Expected Impact

With these changes, users will find it easier to compare statistical data across different screens. This will lead to more comprehensive and accurate performance analysis, and is expected to improve the overall usability of Locust.

[cyberw]

Graphing percentiles over time is kind of a weird thing, as the average 95th percentile (in the graph) over a run is not the same as the 95th percentile for the whole test.

And with few requests per time interval, percentiles are likely to be all over the place, especially higher percentiles (that's why we dont use 99th in the graph)

I kind of think the current choice of percentiles make sense, but I get that they feel inconsistent. Adding 95th percentile to the stats screen by default makes some sense though (btw, these are all configurable https://docs.locust.io/en/stable/configuration.html#customization-of-statistics-settings)

[cyberw]

What do you think @andrewbaldwin44 ? Maybe we should replace 90th percentile in the stats with 95th just to make it consistent? There's already so many columns in that page :) Maybe add a link to the customization documentation on that page too, I think it would be really useful...

[andrewbaldwin44]

I agree with you @cyberw, if it is already configurable in both the table and the charts, I'm not sure if it makes sense for us to change it. Especially considering that different users will always have different opinions on what columns should be displayed.

I have another suggestion here, what would you think of allowing the users to select which columns they want to be displayed. I've seen some other load testing tools offer this feature and I think it could be useful to allow the user to focus on the data they care about

[cyberw]

I was thinking about that. If it can be done without becoming messy it would be great!

[FooQoo]

@cyberw, @andrewbaldwin44

Thank you for guiding me through the customization process. Following your instructions, I was able to successfully customize the charts screen. I hadn't fully grasped that the 95th percentile was already adopted in the charts screen, but after your explanation, I now understand the appropriateness of this choice.

Additionally, as @andrewbaldwin44 suggested, adding the ability for users to edit columns in the statics screen, similar to the charts screen, would greatly enhance convenience. I would be delighted if this suggestion were implemented. It would allow users to focus more on the data that matters to them, thereby significantly improving the Locust user experience.

[FooQoo]

This issue has been resolved by PR #2550, so I close it.