The Backend Engineering Show with Hussein Nasser

By Hussein NasserTechnology

The Backend Engineering Show with Hussein Nasser episodes

August 30, 2024 Windows vs Linux Kernel
Fundamentals of Operating Systems Course
https://os.husseinnasser.com
Why Windows Kernel connects slower than Linux
I explore the behavior of TCP/IP stack in Windows kernel when it receives a RST from the backend server especially when the host is available but the port we are trying to connect to is not. This behavior is exacerbated by having both IPv6 and IPv4 and if the happy eye ball protocol is in place where IPv6 is favorable.
0:00 Intro
0:30 Fundamentals TCP/IP
3:00 Unreachable Port Behavior
6:00 Client Kernel Behavior (Linux vs Windows)
11:40 Slow TCP Connect on Windows
15:00 localhost, IPv6 and IPv4
20:00 Happy Eyeballs
28:00 Registry keys to change the behavior
31:00 Port Unreachable vs Host Unreachable
https://daniel.haxx.se/blog/2024/08/14/slow-tcp-connect-on-windows/

38 min
August 25, 2024 Running out of TCP ephemeral source ports

In this episode of the backend engineering show I describe an interesting bug I ran into where the web server ran out of ephemeral ports causing the system to halt.

0:00 Intro
0:30 System architecture
2:20 The behavior of the bug
4:00 Backend Troubleshooting
7:00 The cause
15:30 Ephemeral ports on loopback

21 min
May 20, 2024 io uring gets even faster
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/[email protected]/?s=09

17 min
May 07, 2024 They made Python faster with this compiler option
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
30 min
April 29, 2024 How Apache Kafka got faster by switching ext4 to XFS
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

34 min
March 05, 2024 Google Patches Linux kernel with 40% TCP performance
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/[email protected]/
Discovering Backend Bottlenecks: Unlocking Peak Performance
https://performance.husseinnasser.com
15 min
February 29, 2024 Database Torn pages
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

16 min
February 28, 2024 Cloudflare Open sources Pingora (NGINX replacement)
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

32 min
February 19, 2024 The Internals of MongoDB
https://backend.win
https://databases.win

I’m a big believer that database systems share similar core fundamentals at their storage layer and understanding them allows one to compare different DBMS objectively. For example, How documents are stored in MongoDB is no different from how MySQL or PostgreSQL store rows.
Everything goes to pages of fixed size and those pages are flushed to disk.

Each database define page size differently based on their workload, for example MongoDB default page size is 32KB, MySQL InnoDB is 16KB and PostgreSQL is 8KB.

The trick is to fetch what you need from disk efficiently with as fewer I/Os as possible, the rest is API.

In this video I discuss the evolution of MongoDB internal architecture on how documents are stored and retrieved focusing on the index storage representation. I assume the reader is well versed with fundamentals of database engineering such as indexes, B+Trees, data files, WAL etc, you may pick up my database course to learn the skills.
Let us get started.

45 min
February 19, 2024 The Beauty of Programming Languages
In this video I explore the type of languages, compiled, garbage collected, interpreted, JIT and more.

19 min

About The Backend Engineering Show with Hussein Nasser

From the publisher's feed

Welcome to the Backend Engineering Show podcast with your host Hussein Nasser. If you like software engineering you’ve come to the right place. I discuss all sorts of software engineering technologies and news with specific focus on the backend. All opinions are my own.