docs: replace some mermaid charts with excalidraw

[hagen1778]

This is an attempt to replace some of the mermaid diagrams with excalidraw diagrams. Excalidraw is supposed to make those diagrams look better and still keep the source updateable.

---

I have attempted to update only diagrams that aren't good looking and could be complex in understanding or managing.

[cubic-dev-ai]

2 issues found across 8 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="docs/victorialogs/security-and-lb.md">

<violation number="1" location="docs/victorialogs/security-and-lb.md:68">
P2: The referenced image file is not present in the repository, so this diagram will render as a broken image. Add the image asset (or revert to the previous diagram) so the doc stays self-contained.</violation>

<violation number="2" location="docs/victorialogs/security-and-lb.md:407">
P2: The referenced image file is not present in the repository, so this diagram will render as a broken image. Add the image asset (or revert to the previous diagram) so the doc stays self-contained.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

No issues found across 8 files

[kapouer]

I am baffled by the huge step back in the documentation indexability and formatting caused by this PR.
Markdown graphs will be readable in ten years.
Excalidraw won't.

[hagen1778]

Markdown graphs will be readable in ten years.

@kapouer could you please elaborate on it?

I understand how easier it is to maintain the mermaid graph - you can patch it right in the .md file, no knowledge of excalidraw required. That's for sure.
The drawback of this ability is that complex mermaid diagrams are too bulky. Take an example of HA setup:

This diagram is pretty simple, btw. But it takes so much space to explain a very simple concept.
The hand-drawn version of it is smaller in size and is just easier to read:

So that's a tradeoff between maintainability and visual aspect. This PR is a suggestion, it can be accepted or declined based on amount of pros&cons it provides.

[kapouer]

I understand the need for more compact diagrams (did you try to render it with elk, or optimize it using some LLM ?).
However those are not exactly the same two diagrams, so it's no wonder one is less compact.

[hagen1778]

did you try to render it with elk, or optimize it using some LLM?

I did. And I didn't like what I got. Getting better at it is always an option. But I think the price for that outweighs the pros.

Please note, I have no intention to reduce docs quality. If maintainers think it got worse - they can just reject the request.

However those are not exactly the same two diagrams, so it's no wonder one is less compact.

I have intentionally removed what I thougt has low informational impact or is confusing.

[func25]

Mermaid is easy for creating diagrams, but it turns out to be hard to control style, spacing, alignment, etc so it is not a great visualization tool. We have very few images in the documentation, so maintainability effort is low. Using Excalidraw is fine and results in higher quality.

[func25]

Thanks for your contribution to the docs

[valyala]

FYI, I removed the docs/victorialogs/security-and-lb-search-auth.webp image in the commit 4ba11fe , because it was incorrect. It didn't match the contents of the chapter it was put into. This chapter - https://docs.victoriametrics.com/victorialogs/security-and-lb/#search-authorization - describes how to set up load balancing among vlselect nodes in a single cluster, while the removed image contained two independent clusters. @hagen1778 , could you create the correct image and return back it to the chapter? It would be great to have clear images for other chapters at https://docs.victoriametrics.com/victorialogs/security-and-lb/ too.

[hagen1778]

Follow-up PR #1474 with images updates.