The Backend Engineering Show with Hussein Nasser

The User Interface/User Experience has great impact on the backend architecture and scalability. In this podcast I discuss three UI/UX that affected backend design and scalability. 0:00 Intro 1:40 UI vs UX 4:30 Google Chrome OmniBox 12:30 1 out of X Page 20:00 YouTube Notification Resources https://blog.apnic.net/2020/08/21/chromiums-impact-on-root-dns-traffic/ Fundamentals of Backend Engineering Design patterns udemy course (link redirects to udemy with coupon) https://backend.husseinnasser.com

In this video I explain how DHCP work and how it updates DNS entries for new hosts joining the network. I'll also mention Zero Config 0:00 Intro 1:00 the Network configuration 6:00 Showing DHCP in Wireshark 6:30 DHCP Discover 14:40 DHCP Offer 19:00 DHCP Request 21:30 DHCP ACK 22:00 How DHCP Updates DNS 26:15 Zero Configuration (mDNS, Link-local) Resources Dhcp https://datatracker.ietf.org/doc/html/rfc1541 Dynamic updates , dhcp RFC2136 https://datatracker.ietf.org/doc/html/rfc2136 https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/xe-3se/3850/dhcp-xe-3se-3850-book/dhcp-client-option-12.pdf RFC 1497 https://www.rfc-editor.org/rfc/rfc1497.html https://www.rfc-editor.org/rfc/rfc6762#ref-Zeroconf Link-local https://www.rfc-editor.org/rfc/rfc3927

Fundamentals of Backend Engineering Design patterns udemy course (link redirects to udemy with coupon) https://backend.husseinnasser.com Certificates provide a way to authenticate both the server and the client and are included as part of the TLS handshake. However, the certificates can be large because the full certificate chain is included in the handshake. The large certificates can go up to 10KB in size and take multiple segments to deliver and assemble. RFC 8879 discusses how TLS compression can be achieved, I discuss that in this podcast. Enjoy. 0:00 Intro 4:15 Certificate Chain 6:00 Faking the chain 8:50 Certificate Stores 10:30 Including ROOT cert in the chain 12:00 The performance penalty of large certificate chain 20:15 RFC 8879 TLS Certificate Compression 23:00 How Compression Works in TLS 1.2 vs TLS 1.3 30:30 What could go wrong? Resources https://datatracker.ietf.org/doc/rfc8879/ https://www.rfc-editor.org/rfc/rfc5246 https://www.rfc-editor.org/rfc/rfc6928.html

Two new vulnerabilities in openssl were discovered, we discuss them in this video https://www.openssl.org/news/secadv/20221101.txt

Google recent paper on protective load balancing in TCP attempts to improve packet drops and latency by making the host change the flow path using the IPv6 Flow label. The Linux kernels gets the PLB support in Linux 6.2 this December, let us discuss with this is.   

In this episode of the backend engineering show I go through an article I wrote discussing NodeJS Asynchronous I/O https://medium.com/@hnasr/when-nodejs-i-o-blocks-327f8a36fbd4 Learn the fundamentals of network engineering, get my udemy course https://network.husseinnasser.com Buy me a coffee if you liked this  https://www.buymeacoffee.com/hnasr 0:00 3:00 Part 1 Socket/IO 9:48 Part 2 File I/O 12:42 Part 3 DNS 16:22 Part 4 NodeJS Single Threaded 19:10 Part 5 NodeJS Thread Pool 21:23 Part 6 DNS lookup bottleneck in Node

Buy me a coffee if you liked this https://www.buymeacoffee.com/hnasr In this podcast I explain the NGINX internal process architecture, how NGINX spins up multiple processes per core, how each process is pinned to a CPU core for minimum context switching,  how NGINX accepts connections , parses requests and talks to the backend.   Get my introduction to NGINX udemy course  https://nginx.husseinnasser.com

Cloudflare identified several limitations in NGINX architecture and decided to write their own reverse proxy. 0:00 Intro 1:53 What NGINX is used for 3:37 NGINX Architecture 7:52 NGINX Limitations 17:12 Cloudflare Pingora Buy me a coffee if you liked this https://www.buymeacoffee.com/hnasr Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com Fundamentals of Database Engineering udemy course (link redirects to udemy with coupon) https://database.husseinnasser.com Introduction to NGINX (link redirects to udemy with coupon) https://nginx.husseinnasser.com Python on the Backend (link redirects to udemy with coupon) https://python.husseinnasser.com Become a Member on YouTube https://www.youtube.com/channel/UC_ML5xP23TOWKUcc-oAE_Eg/join Resources Resources: https://blog.cloudflare.com/how-we-built-pingora-the-proxy-that-connects-cloudflare-to-the-internet/ https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/amp/

In this episode of the backend engineering show I discuss the evolution of multi-threading apps, their pros and cons and then I go through 5 threading model and how they interleave with backend connection management between the threads and requests handlings. Enjoy To learn more about networking fundamentals check out my udemy course Fundamentals of Networking for Effective Backends Head to https://network.husseinnasser.com for a discount coupon 0:00 Intro 2:00 Single Threading 6:30 Multi-Threading 14:15 Connection Listener 20:15 How Connections are Established 29:00 Single Listener/Worker thread 33:30 Single Listener, Multiple Worker threads 39:00 Single Listener, Multiple Workers with load balancing 42:10 Multiple Listeners on the same port (SO_REUSEPORT) 45:20 Multiple Single Threaded Backend Buy me a coffee https://www.buymeacoffee.com/hnasr

Memcached is an in memory cache with one major feature be a transient cache. Memcached has a very simple design. It was originally designed to help with database load by storing the query result in memory to avoid further querying the database. By default it has no authentication, a simple text protocols, servers don’t talk to each other. This video discuss the architecture of the cache, design choices and have some critics of the design choices. I go through a demo at the end using docker, telnet and nodes. Enjoy 0:00 Intro 4:40 What is Memcached? 7:45 Memory management 16:00 LRU 25:17 Threading and Connections 30:40 Read Example 34:30 Write Example 36:17 Write and Read collisions 39:40 Locking 40:30 Distributed Cache 43:30 Memcached with Docker/Telnet/NodeJS 45:00 Spin up a Memcached Docker container and telnet 52:17 Memcached and NodeJS 56:15 Four Memached Servers with NodeJS 01:01:00 Summary Resources https://www.cloudflare.com/learning/ddos/memcached-ddos-attack/ https://holmeshe.me/understanding-memcached-source-code-IV/ https://github.com/memcached/memcached/blob/master/doc/protocol.txt https://docs.oracle.com/cd/E17952_01/mysql-5.6-en/ha-memcached-using-threads.html https://holmeshe.me/understanding-memcached-source-code-I/ https://docs.oracle.com/cd/E17952_01/mysql-5.6-en/ha-memcached-using-memory.html https://support-acquia.force.com/s/article/360005256114-Memcached-in-detail https://www.alibabacloud.com/blog/redis-vs-memcached-in-memory-data-storage-systems_592091 https://www.usenix.org/system/files/conference/nsdi13/nsdi13-final197.pdf https://memcached.org/blog/persistent-memory-2/ https://memcached.org/blog/modern-lru/ Buy me a coffee https://www.buymeacoffee.com/hnasr