AWS Classroom notes – 15/Nov/2019

Auto Scaling

  • Lets create an Auto Scaling Group with an AMI (apache2, php and stress)
  • Create a Launch Configuration by selecting
    • AMI
    • Instance type
    • Storage
    • Security Group
    • KeyPair
  • Create AutoScaling Group linked with Launch Configuration
    • Configure Increase Scenario (eg average cpu utilization > 75 for period of 5 minutes)
    • Configure Decrease Scenario (eg average cpu utilization <= 50 for period of 5 minutes)
  • Then you should see the machine running
  • Login into one machine to create artificial load using stress
stress --cpu 8 --io 4 --vm 2 --vm-bytes 128M -v --timeout 10m
  • To have a closer look, create one more ssh login session and execute htop and observe cpu

Load Balancers

  • With Auto scaling group, you will have multiple servers where your application is running, we need to give unique ip/dns to the user
  • For this we go with load Balancers
  • In AWS, we have three kinds of Load balancers
    • Classic Load Balancer : Layer 4 and Layer 7
    • Application Load Balancer: Layer 7
    • Network Load Balancer: Layer 4
  • Load Balancer needs to know which machines are healthy, to do this we have health checks
  • Generally there are two kinds of LBs
    • Layer-4 Loadbalancers: LBs which are aware of ip and port
    • Layer-7 Loadbalancers: LB which are aware of http,url, ip and port
  • Refer here
  • Create a Classic Load balancer by configuring health checks
  • Access the appplication using classic loadbalancers dns name.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

About continuous learner

devops & cloud enthusiastic learner