The Backend Engineering Show with Hussein Nasser Hussein Nasser

Fundamentals of Operating Systems Course
https://os.husseinnasser.com

Linux I/O expert and subsystem maintainer Jens Axboe has submitted all of the IO_uring feature updates ahead of the imminent Linux 6.10 merge window.
In this video I explore this with a focus on what zerocopy.


0:00 Intro
0:30 IO_uring gets faster
2:00 What is io_uring
7:00 How Normal Copying Work
12:00 How Zero Copy Works
13:50 ZeroCopy and TLS


https://www.phoronix.com/news/Linux-6.10-IO_uring
https://lore.kernel.org/io-uring/fef75ea0-11b4-4815-8c66-7b19555b279d@kernel.dk/?s=09

Fundamentals of Operating Systems Course
https://oscourse.win

Looks like fedora is compiling cpython with the -o3 flag, which does aggressive function inlining among other optimizations.

This seems to improve python benchmarks performance by at most 1.16x at a cost of an extra 3MB in binary size (text segment). Although it does seem to slow down some benchmarks as well though not significantly.

O1 - local register allocation, subexpression elimination
O2 - Function inlining only small functions
O3 - Agressive inlining, SMID

0:00 Intro
1:00 Fedora Linux gets Fast Python
5:40 What is Compiling?
9:00 Compiling with No Optimization
12:10 Compiling with -O1
15:30 Compiling with -O2
20:00 Compiling with -O3
23:20 Showing Numbers

Backend Troubleshooting Course
https://performance.husseinnasser.com

https://oscourse.win



Allegro improved their Kafka produce tail latency by over 80% when they switched from ext4 to xfs. What I enjoyed most about this article is the detailed analysis and tweaking the team made to ext4 before considering switching to xfs. This is a classic case of how a good tech blog looks like in my opinion. 



0:00 Intro

0:30 Summary

2:35 How Kafka Works?

5:00 Producers Writes are Slow

7:10 Tracing Kafka Protocol 

12:00 Tracing Kernel System Calls

16:00 Journaled File Systems

21:00 Improving ext4

26:00 Switching to XFS





Blog

https://blog.allegro.tech/2024/03/kafka-performance-analysis.html

Get my backend course https://backend.win



Google submitted a patch to Linux Kernel 6.8 to improve TCP performance by 40%, this is done via rearranging the tcp structures for better cpu cache lines, I explore this here.

0:00 Intro
0:30 Google improves Linux Kernel TCP by 40%
1:40 How CPU Cache Line Works
6:45 Reviewing the Google Patch

https://www.phoronix.com/news/Linux-6.8-Networking
https://lore.kernel.org/netdev/20231129072756.3684495-1-lixiaoyan@google.com/


Discovering Backend Bottlenecks: Unlocking Peak Performance
https://performance.husseinnasser.com

0:00 Intro

2:00 File System Block vs Database Pages

4:00 Torn pages or partial page

7:40 How Oracle Solves torn pages

8:40 MySQL InnoDB Doublewrite buffer

10:45 Postgres Full page writes

Get my backend course https://backend.win



Cloudflare has announced they are opening sources Pingora as a networking framework! Big news, let us discuss 



0:00 Intro

0:30 Reasons why Cloudflare built Pingora?

3:00 It is a framework! 

7:30 What in Pingora?

11:50 Security in Pingora

13:45 Multi-threading in Pingora

21:00 Customization vs Configuration

25:00 Summary







⁠https://blog.cloudflare.com/pingora-open-source/?utm_campaign=cf_blog&utm_content=20240228&utm_medium=organic_social&utm_source=twitter⁠