Learning logs in Aug

  1. Export large tables in MySQL
  2. Bash completion on debian 9


RDS as-a-fckin-service

AWS RDS document: Depending on the DB instance class and the amount of storage, it can take up to 20 minutes before the new instance is available.

Reality:

  • RDB instance status: creating
  • RDS stuck in this fucking step nearly 2 hours and couting
  • db-fuck-as-a-service


Mindset for building HA and scalable system

System or infrastructure must have

  • Fault tolerance
  • No single point of failure
  • More than one or two security layers
  • Auto-failover without requiring human intervention
  • Heartbeat monitoring on all running components
  • Infrastructure as code


Increase EBS volume of AWS on linux

Problem

  • A disk volume 32GB /dev/xvdf1 is mounted into /var/lib/mysql
  • This volume is out of space, need to be extend size to 64GB
  • Extended to 64GB on aws console, but from ec2 point of view, it’s just 32GB

Rootcause: didn’t merge partition after extending and resize fs


Understanding top command

top is a monitoring program which is used frequently for tracking process’s resource usage and its activity in real-time, show current tasks being serviced by the kernel, help discovering and diagnosing overload or capacity of system by seeing CPU & Mem usage. It’s available under many Unix/Linux operating systems.

Keyword: top, uptime, users, load average, process/thread state, CPU operation