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 loo...
Oct 12, 2022•26 min
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
Oct 07, 2022•16 min
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 ...
Oct 04, 2022•26 min
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-Thread...
Sep 01, 2022•50 min
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, teln...
Aug 27, 2022•50 min
In this episode of the backend engineering show I go through the main job of the network interface controller (NIC for short) and how the datacenter is pushing it to the limit by allowing it to do more TCP/IP processing, creating what is being popularized as smartNIC. 0:00 Intro 1:20 What is a NIC? 3:40 NIC job 8:00 When does the OS get involved 12:40 Promiscuous mode 14:00 SmartNIC 18:30 Disadvantages Resources https://developer.nvidia.com/networking/ethernet-adapters https://www.theregister.co...
Aug 15, 2022•21 min
In this episode of the backend engineering show I discuss consistent hashing a very important algorithm in distributed computing specially in database systems such as Apache Cassandra and DynamoDB. 0:00 Intro 2:00 Problem of Distributed Systems 5:00 When to Distribute 7:00 Simple Hashing 9:30 Where Simple Hashing Breaks 11:40 Consistent Hashing 18:00 Adding a Server 21:15 Removing a Server 22:30 Limitations Buy me a coffee https://www.buymeacoffee.com/hnasr
Aug 06, 2022•25 min
In this episode of the backend engineering show I go through and discuss the Homa Protocol paper which attempts to replace TCP as a protocol in the data centers. I learned a lot from this paper, I have my criticisms of certain aspects, timestamps for topics discussed below. It appears there is a path to replace TCP in the datacenter and professor John tries to explain this path. Referenced materials mentioned in the episode Overview paper https://web.stanford.edu/~ouster/cgi-bin/papers/replaceTc...
Aug 01, 2022•1 hr 24 min
ByteDance, the company behind TikTok is proposing few patches to the linux kernel to make kernel reboots via kexec go from 500ms down to 15 ms saving huge time in updating kernel on thousands of machines. Let us discuss this 0:00 Intro 1:30 Linux Kernel Reboot Options 2:30 how kexec works 4:00 The optimization 5:00 Going through the patch 6:00 Updating Servers at TikTok scale 9:00 Summary https://www.phoronix.com/news/Bytedance-Faster-Kexec-Reboot https://lore.kernel.org/lkml/20220725083904.5655...
Jul 26, 2022•11 min
We discuss the CVE-2022-2274 OpenSSL Vulnerability. The OpenSSL 3.0.4 release introduced a serious bug in the RSA implementation for X86_64 CPUs supporting the AVX512IFMA instructions. This issue makes the RSA implementation with 2048 bit private keys incorrect on such machines and memory corruption will happen during the computation. As a consequence of the memory corruption an attacker may be able to trigger a remote code execution on the machine performing the computation. 0:00 Intro 1:00 CVE...
Jul 15, 2022•9 min
Postgres 15 introduces a new syntax to treat nulls as not distinct. This will allow developers to create a unique constraint on nullable fields and have inserts with nulls fail instead of having it allowed based on today's standard. 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 https://b...
Jul 13, 2022•7 min
memchr() is a function that searches in a memory block for a character, this has been recently improved in the latest linux patch and we can learn something from this improvement I think, lets discuss. https://www.phoronix.com/scan.php?page=news_item&px=Linux-Kernel-Faster-memchr Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com
Jul 12, 2022•7 min
Amazon Aurora PostgreSQL-Compatible Edition now supports PostgreSQL major version 14 (14.3). Let us discuss this news. https://aws.amazon.com/about-aws/whats-new/2022/06/amazon-aurora-supports-postgresql-14/ 0:00 Intro 1:00 Database on the Cloud options 3:45 Amazon Aurora supports Postgres 14 6:00 Postgres 14 vs Postgres 13
Jul 11, 2022•12 min
Rogers Communications, the Canadian ISP is down. One of its ASNs (they have many) is AS812 with over 5 million IP addresses. Tried a few and none of them can be pinged from the US (not sure if ICMP is disabled or not) This is a huge deal for all Canadians and businesses affected. So sorry for every one who is affected by this, and kudus to all the engineers at Rogers working to fix this for the past what? 11 hours now? If an ASN goes dark like a Facebook or a Cloudflare that isn't a big deal you...
Jul 11, 2022•14 min
In this episode of the backend engineering show I’ll discuss Fill Factor index property, an important key parameter for a good performing database. I will also discuss how it is a double edge sword and can break or Make your db. Chapters 0:00 Intro 1:48 Start of the Show 4:30 Database Storage Representation 6:30 IO Cost 10:00 Index Page 13:30 Page Splits Cost 18:00 Indexing UUIDs 19:45 FillFactor 23:15 Bad FillFactor values 26:40 Fragmentation In Indexes 30:30 Summary Fundamentals of Networking ...
Jul 11, 2022•35 min
In this video I discuss early hints HTTP 103 status code, the problem it solves and the challenges it has.
Jul 04, 2022•11 min
YugabyteDB is a postgres compatible and cloud native database. Read committed isolation level is a critical feature and adding it might lure more postgres customer’s to move to the cloud native database. But will they compete in front of Google’s new AlloyDB ? 0:00 Yogabyte implements Read committed 4:20 Isolation Levels 8:40 Can YugabyteDB compete with Google AlloyDB? https://www.theregister.com/2022/06/28/yugabytedb_215/ https://docs.yugabyte.com/preview/architecture/transactions/explicit-lock...
Jun 30, 2022•12 min
Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com Transport Layer security or TLS is a protocol that encrypted the communication between client and server. TLS can also be used to authenticate the server, when the client also requires authentication this is called Mutual TLS and this is the topic of today’s show. 0:00 Introduction 2:00 What is TLS? 7:00 Server Authentication TLS 14:00 Advantages of one way TLS 1...
Jun 27, 2022•51 min
In this episode we go through the cloud flare outage blog. https://blog.cloudflare.com/cloudflare-outage-on-june-21-2022/ Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com
Jun 22, 2022•25 min
In this episode of the backend engineering show I go through the Extensible Prioritization Scheme for HTTP. This RFC addresses the problem in HTTP where the client prefers certain requests to be served before others. This RFC was designed by Lucas Pardue from Cloudflare and Kazoo Oku from Fastly. 0:00 The Request Priority Problem 13:00 How RFC 9218 addresses the problem 25:00 HTTP/1.x Backends 32:00 Summary RFC 9218 https://datatracker.ietf.org/doc/rfc9218/
Jun 20, 2022•36 min
In this video I explain what is a zero day vulnerability or attack. Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com
Jun 05, 2022•6 min
IPv4 UniCast Extensions Project attempts to unreserve old IPv4 subnets so they are publicly addressable. Is it worth it? Let us discuss https://blog.apnic.net/2022/05/31/cutting-down-on-ip-address-waste/Unicast Use of the Formerly Reserved 127/8 https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127/ Unicast Use of the Lowest Address in an IPv4 Subnet https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-lowest-address/ Unicast Use of the Formerly Reserved 240/4 https://datatr...
Jun 02, 2022•11 min
Fantastic gains in Postgres 15! improved sorting by 371%. Normally you can avoid sorting by using an index access path. However, you can’t always have an index on every group by, order by, join or distinct predict. This will come handy. Let us discuss Resources https://www.phoronix.com/scan.php?page=news_item&px=PostgreSQL-15-Faster-Sort https://techcommunity.microsoft.com/t5/azure-database-for-postgresql/speeding-up-sort-performance-in-postgres-15/ba-p/3396953#change3 https://www.postgresql...
Jun 01, 2022•10 min
In this episode of the backend engineering show I discuss UDP hole punching in details. Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com
May 30, 2022•17 min
As a new parent, you get exposed to a whole new world. There is this new toddler song “Five little monkeys jumping on the bed” where it starts with five monkeys jumping on the bed and one falls off the bed and the mom calls the doctor and then another monkey falls and the mom calls the doctor again. This keeps going until all monkeys are no longer on the bed. This clearly looks like a software engineering problem. In the face of it is extreme inefficiency in IO with the mom calling the doctor 5 ...
May 29, 2022•9 min
Eric Dumazet, a Linux kernel and a Google Principal software engineer pushed a new change to Linux to support a new feature in Linux called BIg TCP. How about we discuss this resources https://www.phoronix.com/forums/forum/software/general-linux-open-source/1325637-linux-5-19-networking-brings-big-improvements-with-big-tcp-purelifi-more-hardware https://patchwork.kernel.org/project/netdevbpf/patch/20220524203159.1189780-1-kuba@kernel.org/https://datatracker.ietf.org/doc/html/rfc2675
May 28, 2022•14 min
Database logging is a critical feature to maintain durability, in this show I discuss them in details 0:00 intro 1:00 ad 3:30 Start of the Show 6:00 What is commit 9:30 What if a commit fails half way 11:00 WAL 23:00 Checkpointing 27:00 fsync 33:00 Undo logs Get $20 off of your first order of cometeer quality delicious coffee https://cometeer.com/husseinnasser use coupon HUSSEIN20 ☕️
May 26, 2022•41 min
In this video I discuss the developer mental health, stress, pressure, expectation, how to understand and shed light on the issues, and what might cause it all. Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com
May 20, 2022•19 min
In this video I explain how we can use two-phase commit protocol works to achieve atomic distributed transaction. 0:00 What is atomicity 3:00 Distributed Transaction 6:00 Two phase commit protocol 13:00 Limitations of Two phase commit protocol 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.co...
May 11, 2022•16 min
Welcome to another database question. In this question I created a community poll question and provided some answers. All answers can be correct of course but the question is what is the most efficient? this is what I try to explore in this video and compare how different database platforms such as mysql or Postgres differ in those implementations; Table T with three integer fields A, B and C. A has a primary key clustered index. B has a secondary index. Which query is more likely to be the most...
May 04, 2022•18 min
