Amazon Web Services: AWS elasticity Understanding and using Bootstrapping

In this blog we will discuss AWS elasticity Understanding and using Bootstrapping

Bootstrapping

-The process of automatically setting up your instances

-Example

   -Install Windows Updates

   -Create Custom DNS names

   -Register with an ELB

   -Mount additional drives

   -start specific services

   -Copy files from S3

   -Install latest version of the software

   -Modify firewall configuration

Bootstrapping tools and tricks

-Cloud-init is installed on LINUX AMIs by default

-EC2 config (windows service) is installed on the windows

   -Windows activation

   -Hostname changes

   -Sysprep

   …..and more

-Scripting ( bash, powershell) or config management(chef, puppet)

-Instance information http://169.254.169.254/latest/meta-data/

-User information http://169.254.169.254/latest/User-data/

-Dynamic Information http://169.254.169.254/latest/ 

Understanding User data

-Limited to 16K in sinze

-Can be set through AWS management Console or AWS command line tool

-Linux:embed scripts with # (cloudinit)

-Windows:embed scripts with <script>(EC2config)

-Also interact with AWS services using ec2 command line tools

Bootstrapping Best practices and Principles

-Creating a good Bootstrapping AMI is great...but theres more

-Dynamic as possible:Discovery or registration of instances

-Dyanmic as possible: graceful departures

-Example: MySQL replica failure(Died, poor performance....)

   -Failure Detection ( Ping, slow slave status.....)

   -smooth addition (Duplicate source DB instance  id, use as an api, maual)