How to resolve Insufficient Instance Capacity issue of EC2 server by Raj Gupta

Issue:-

If We get an InsufficientInstanceCapacity error when we try to launch an instance or restart a stopped instance,

This is because AWS does not have currently enough available EC2 server to provide you..

Solution:-

1. Wait a few minutes and then create EC2 once again; capacity can shift frequently.
2. Submit a new request with a reduced number of instances. For example, if you're making a single request to launch 15 instances, try making 3 requests for 5 instances, or 15 requests for 1 instance instead. 
3. If you're launching an instance, submit a new request without specifying an Availability Zone. 
4. If you're launching an instance, submit a new request using a different instance type (which you can resize at a later stage). 
5. If you are launching instances into a cluster placement group, you can get an insufficient capacity error. 
6.  Try creating an On-Demand Capacity Reservation, which enables you to reserve Amazon EC2 capacity for any duration.
7.  Try purchasing Reserved Instances, which are a long-term capacity reservation.