Azure VMSS Auto Upgrade

• For a VMSS to support autoupgrade, Health Extensions needs to be enabled.
  
• Refer Here on the official docs on setting automatic upgrades.
• Ensure auto upgrade is on by executing the following command in azure cli

az vmss update --name phpmyinfo --resource-group vmssdemo --set UpgradePolicy.AutomaticOSUpgradePolicy.EnableAutomaticOSUpgrade=true

* To perform manual upgrade execute the following command

az vmss rolling-upgrade start --resource-group "vmssdemo" --name "phpmyinfo" 

Azure VM Purchasing Options

• To Purchase VM’s In Azure we have 3 major options
  • On-demand:
    • We pay hourly bills based on usage
    • Hourly charge for vms which are running
  • Reservations:
    • We give a commitment of 1 (41% discount) or 3 years (62% discount)
    • Monthly charges
  • Spot VMs: Refer Here