Io_uring, kTLS and Rust for zero syscall HTTPS server

(blog.habets.se)

495 points guntars | 1 comments | 22 Aug 25 03:51 UTC | HN request time: 0.203s | source

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bmcahren ◴[22 Aug 25 05:35 UTC] No.44981313[source]▶

This was a good read and great work. Can't wait to see the performance tests.

Your write up connected some early knowledge from when I was 11 where I was trying to set up a database/backend and was finding lots of cgi-bin online. I realize now those were spinning up new processes with each request https://en.wikipedia.org/wiki/Common_Gateway_Interface

I remember when sendfile became available for my large gaming forum with dozens of TB of demo downloads. That alone was huge for concurrency.

I thought I had swore off this type of engineering but between this, the Netflix case of extra 40ms and the GTA 5 70% load time reduction maybe there is a lot more impactful work to be done.

https://netflixtechblog.com/life-of-a-netflix-partner-engine...

https://nee.lv/2021/02/28/How-I-cut-GTA-Online-loading-times...

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commandersaki ◴[22 Aug 25 20:20 UTC] No.44989337[source]▶

>>44981313 #

I'm sceptical of the efficiency gains with sendfile; seems marginal at best, even in the late 90s when it was at the height of popularity.

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1. kev009 ◴[22 Aug 25 21:11 UTC] No.44989863[source]▶

>>44989337 #

Then you don't understand the memory and protection model of a modern system very well.

sendfile effectively turns your user space file server into a control plane, and moves the data plane to where the data is eliminating copies between address spaces. This can be made congruent with I/O completions (i.e. Ethernet+IP and block) and made asynchronous so the entire thing is pumping data between completion events. Watch the Netflix video the author links in the post.

There is an inverted approach where you move all this into a single user address space, i.e. DPDK, but it's the same overall concept just a different who.

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