Jenkins has a master-agent architecture. Agent, i.e., worker is also called “node” in Jenkins terminology. Master distributes jobs to agents. Agent vs inbound agent You may wonder why there are t...

Jenkins pipeline Jenkins pipeline is probably the most important concept that a newbie needs to learn. Whenever you write a Jenkinsfile, you write a pipeline. When I started to use and learn Jenki...

We are all familiar with the concept of role based authorization. It is designed around answering this question: is role X allowed to do Y on object Z? Postgres is no exception. How to allow multi...

Setup for newbie Install rustup. Install rust-analyzer: rustup component add rust-analyzer and config nvim lspconfig and treesitter. Read https://doc.rust-lang.org/stable/book/ Checkout h...

TCP Keepalive https://tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/ Socket in general The first newbie question when doing socket programming is how to tell a socket has received all bytes fr...

SIGALRM and Timeouts If you have done some timer things in Linux, you must be familiar with the concept of Interval Timer. If not, please check out the man page. Below example illustrates how to u...

Channel is usually used together with goroutines. Let’s take an example from k8s source code. This function returns a channel for callers to consume. Inside, it spawns a background goroutine to sen...

Many tools pg_ha_migrations for Ruby on Rails. The core part is this function. It acquires the lock beforehand. Basically, it first waits until no conflicting transaction exits. Then, it acquires ...

Q1. What plan contains? How is it executed? You know what? The part I love most about Postgres codebase is its comments. Very informative and I learned a lot from them. What does a query planner ...

Postgres official documentation Chapter 55. Frontend/Backend Protocol covers all the details about the client-sever binary protocol, which is a based on top of TCP. All communication is through...