The Backend Engineering Show with Hussein Nasser

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://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240/   Unicast Use of the Formerly Reserved 0/8 https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0/ https://twitter.com/TheRealRevK/status/1532033651650830339   Fundamentals of Networking for Effective Backends udemy course (link redirects to udemy with coupon) https://network.husseinnasser.com

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.org/docs/15/release-15.html#id-1.11.6.5.4 https://techcommunity.microsoft.com/t5/sql-server-blog/understanding-sql-server-fast-forward-server-cursors/ba-p/383556

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

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 times in span of 3 minutes. The mom could decide to wait for all monkeys to fall and call the doctor once. A Method that is known as batching. Two problems with this approach; the first is latency the mom can’t wait, she is worried, she needs immediate answer from the doctor for the first monkey that fell. The second problem is we don’t know if more monkeys are going to fall off the bed, so while the mom waiting, the first monkey will be in pain and will “starve”. We makes decisions like this constantly in software engineering. In some database systems for example commits from transactions are grouped and batched for few microseconds/milliseconds so more commits can arrive and the database can flush/fsync the WAL once. This is specially important in highly concurrent system because disk fsync is costly and bypasses the operating system cache. However, this comes at a cost of slight delay in transaction commits but less IO in general. To batch or not to batch. The five little monkey problem doesn’t have one right solution it all depends.

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

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 ☕️

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

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.com

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 efficient? 0:00 Intro 1:00 The Question 3:20 WHERE C BETWEEN 50,50000 5:30 WHERE B BETWEEN 50,50000 13:20 WHERE C BETWEEN 50,50000 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

WhatsApp Went down again, this is an early report with brief analysis, enjoy.   https://engineering.fb.com/2020/10/21/networking-traffic/how-facebook-is-bringing-quic-to-billions/