A common devops task is build logging pipeline with ELK stack (Elasticsearch, Logstash, Kibana). Suppose the application is written in Java and currently use log4j’s…
Update 2023: the practice outlined in this post has been outdated. This post is for archive ony. One of the reasons I prefer CloudFormation over…
This post is a summary of VMware’s white paper Introduction to VMware vSphere. ESXi is the hypervisor (virtualization layer) on bare metal servers that abstracts…
Most of the text processing can be processed by awk and sed. Sed is non-interactive stream editor that allows you to specify all editing instructions…
Cron and anacron We all know cron is a job scheduler. Many admin uses crontab to manage scheduled task. It is also important to know…
These are the things quite confusing or abstract while I was at school but now makes lots of sense after many years working with different…