The Backend Engineering Show with Hussein Nasser

In this episode, I go through the Facebook detailed article regarding their October 4th, 2021 outage and discuss it in length. enjoy Facebook blog: https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/ 0:00 Introduction on Facebook Networking Architecture 12:00 The Cause of the Outage 17:00 What’s DNS 23:00 DNS Servers disabled BGP ads 27:00 Could the outage have been prevented? 32:00 Why did it take so long? 38:00 Why you can’t just flip everything on 41:30 Summary 🧑‍🏫 Courses I Teach https://database.husseinnasser.com https://nginx.husseinnasser.com https://python.husseinnasser.com Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg Support my work on PayPal https://bit.ly/33ENps4 🏭 Backend Engineering Videos in Order https://backend.husseinnasser.com 💾 Database Engineering Videos https://www.youtube.com/playlist?list=PLQnljOFTspQXjD0HOzN7P2tgzu7scWpl2

Quick summary of the Facebook, Instagram and WhatsApp outage on Oct 4th 2021

In this episode I discuss my recent flight through Alaskan airlines and how they block certain services but allow only texting.

Spook.js is a new transient execution side channel attack which targets the Chrome web browser. We show that despite Google's attempts to mitigate Spectre by deploying Strict Site Isolation, information extraction via malicious JavaScript code is still possible in some cases. Resources https://www.spookjs.com/ https://www.chromium.org/developers/design-documents/site-isolation Paper: https://www.spookjs.com/files/spook-js.pdf Chapters 0:00 Process Isolation in Chrome 8:00 Spook.js subdomain Attack 12:00 Spook.js Extension Attack 13:00 Summary Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg Support my work on PayPal https://bit.ly/33ENps4 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

In this episode of the backend engineering show, I’ll go through the SSL Stripping attack, what caused it, what were the mitigations enforced to solve it, and why it is still a problem. 0:00 Intro 2:10 The Web Security Model 14:30 SSL Stripping Example 22:00 How to Solve SSL Stripping? 27:00 Limitations of HSTS 31:00 Summary Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg Support my work on PayPal https://bit.ly/33ENps4 🧑‍🏫 Courses I Teach https://husseinnasser.com/courses

Let us take a moment to appreciate the TCP/IP design by discussing it.

The gRPC team just submitted a proposal to support HTTP/3. This is big news and we have been waiting for a long time for this. In this show, I’ll discuss why would you want gRPC, why gRPC picked HTTP/2, what is actually wrong with HTTP/2 and what HTTP/3 solves. And Finally, I’ll discuss what is wrong with HTTP/3 and pitfalls that you as gRPC user might run into. Let us discuss! 0:00 Intro 1:30 why gRPC 5:20 gRPC & HTTP/2 7:30 gRPC & HTTP/3 8:50 What is wrong with HTTP/2 29:30 What is good about HTTP/3 37:00 What’s wrong with HTTP/3 Resources https://github.com/grpc/proposal/pull/256/files Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg Support my work on PayPal https://bit.ly/33ENps4

I discuss keepalive in TCP and HTTP and its pros and cons 0:00 Intro 3:28 What is KeepAlive 8:30 TCP KeepAlive 10:30 Middleboxes and Single-Path TCP 16:30 Middle Boxes and Keepalive 19:30 The FTP KeepAlive trap 25:00 HTTP KeepAlive 30:00 What's a good keepalive timeout? https://daniel.haxx.se/blog/2020/02/10/curl-ootw-keepalive-time/ https://datatracker.ietf.org/doc/html/rfc1122#section-4.2.3.6 https://datatracker.ietf.org/doc/html/rfc793#section-3.5 Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join 🔥 Members Only Content https://www.youtube.com/playlist?list=UUMO_ML5xP23TOWKUcc-oAE_Eg Support my work on PayPal https://bit.ly/33ENps4

In this video I’ll illustrate how a proxy server works under the hood. I Will go through how connection establishment works without a proxy, with an HTTP proxy and finally with HTTPS proxy in tunnel mode and TLS termination mode. 0:00 Intro 1:00 Connection Establishment without a Proxy 5:00 Connection Establishment with an HTTP Proxy 15:22 Connection Establishment with an HTTPS Proxy (Tunnel mode) 19:50 Connection Establishment with an HTTPS Proxy (TLS Termination) cards 16:25 https://youtu.be/PAJ5kK50qp8 connect method

I discuss the concept of process forking, copy on write (COW) aka shadowing, and how Redis the in-memory database take advantage of that for asynchronous snapshotting,    https://redis.io/topics/persistence