Large-scale load testing article

[sniku]

In addition to the article itself. This PR fixes the annoying codeblock indentation.

Before:

After:

The "labels" prop is no longer required for the codeblock

<div class="code-group">
This now works without crashing the project
</div>

[simskij]

Stumbled upon this PR in my notification center and got curious. Thought I'd leave some comments (yeah I know it's WIP). Feel free to just resolve them if you disagree. Great and interesting article! 👏

[imiric]

Nice work! The amount of performance achieved by scaling is impressive! 🎉

[mstoykov]

I would argue that if your script is simple and uses discardResponseBodies the difference is more like 85% , with a 1.5mb json data file(If my memory served) the difference was 50%, but I can't currently find where I've said that 😭 . I would argue some links to benchmark data will be useful here.

Also another thing that compatibility-mode=base does is "significantly" increase the startup time. In the above linked script I ran the script for 60s and in the one case there were additiona minute and 5 seconds (on average) additiona time in the other a secodn and a half for 3500 VUs. Which IMO is "significant" :D

[sniku]

Updated the text. If you have relevant benchmark links, let me know.

[mstoykov]

I would argue you can try to do a test with this and see how much better they will be :). This way when someone doesn't use it and looks at optimizing they can see some example of what the difference si

[sniku]

yeah, that's a fair point, but I don't want to go back to testing for this article :-)
I'll maintain this page, and will likely update it later.

[robingustafsson]

Great article 👏 Just a few grammatical and spelling issues to fix.

[robingustafsson]

This section is really good, but it feels like it shouldn't be in its own article on "Understanding k6 errors" or something like that.

[simskij]

@robingustafsson I suspect there's a negation too much in that sentence? 😅 If so, I agree that it would be nice to have in its own article.

[sniku]

👍 I'll release this as is, and then branch it out to another article :-)

[robingustafsson]

nitpick but it's per <src IP, src port, dst IP, dst port> tuple afaik, so should be able to go beyond 65k if machine has multiple nics with different IPs or target system hostnam is behind a load balancer with different IPs etc.

[sniku]

I'm happy to update that, but I think I'll have to mention that k6 doesn't have support for multiple IPs and discuss this for a while. I don't want to go too much off-topic :-) (here's another hyphen!)

I also think that the limit of 65k is for <src IP, src port>. I don't think the destination IP matters when all 65k ports are already used by the load-gen server. (or maybe I'm missing something).

[ppcano]

@sniku

1 - I am not sure if the location of the article is the best one. The Test Types section follows a structure and convention that differs from this one.

Not sure, move to MISC, Testing Guides, blog, ....?

2 - I think this article should be linked from other articles. For example fine-tuning, stress testing...

[sniku]

@ppcano

1. This article is currently in "Testing Guides" not "Test types" - I think you looked in a wrong place.

2. Sure, we can link it throughout the docs once it's merged.

Let me know if you are OK with this as is or if I should change something :-)

[ppcano]

@sniku oops. Sorry.

2 - Sure! We use the ## See also and the blockquotes patterns in other articles.

3 - I think the title could be improved to be discovered more easily from the sidebar menu.
Running large tests ?

[sniku]

@ppcano

Your title fits in the allotted space, so you win :-)