Re: [PATCH gwproxy v8 2/2] gwproxy: refactor code base to add experimental raw DNS backend

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

On Sun, Sep 07, 2025 at 01:39:05PM +0700, Ahmad Gani wrote:
> I think 65536 is a pretty low memory footprint in modern systems; as Sir
> Alviro noted, it's around 0.25 or 0.5 MB.
> 
> Maybe it's more beneficial to allocate at once in the stack rather than
> add instructions for growing/shrinking the allocated memory?

Yes, it's small. But I prefer to save the space for it. The memory
saving is very beneficial for a small Linux device like Raspberry Pi,
4G modems, or even your lovely home routers.

Also, when you have 65536 clients in a single thread, that doesn't
necessarily mean your DNS mapping are fully used from index 0 to 65535.
A DNS query is a short-lived object. You only need to keep it until the
DNS query receives a response.

Having 65536 outstanding DNS queries is very unlikely even with 100K
concurrent connections. Especially given the cache feature, you will
skip the DNS resolution if identical names are accessed very often. I
believe allocating it lazily is a good way for this design.

If the initial size, 16, feels too low for you. You may consider adding
an option to customize the initial size via CLI args.

-- 
Ammar Faizi