Memory Resource Controller When you exec into a k8s pod, you will find a lot of files under /sys/fs/cgroup/memory. root@kafka-all-in-one-consumer-7567f685c4-8wv8x:/sys/fs/cgroup/memory# ls -l tot...

Envoy is a proxy solution. There are so many proxies in the market: nginx, haproxy, trafik and etc, but why does Envoy stand out? It is because the xDS APIs, or a fancier name, xDS protocol. Envoy ...

Istio used to have a micro-service architecture. However, starting from v1.5, It moved back to a monolithic architecture. This largely simplifies the management of Istio. After v1.5, we only need t...

The purpose of vacuum: recover disk space. Update planner statistics Prevent transaction id wraparound failure how dd dashboard show low row count after failover ...

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...