T2 micro unlimited

While the T2 micro instance with unlimited mode can sustain high CPU utilization for extended periods, there are some important factors to consider in your situation:

1. Baseline performance: Even in unlimited mode, T2 instances have a baseline CPU performance. If your average CPU utilization over a 24-hour period exceeds this baseline, you may experience a performance drop.

2. CPU credits: T2 instances use CPU credits to burst above the baseline. In unlimited mode, you can continue to burst beyond your available CPU credits, but this incurs additional charges.

3. Billing and throttling: If your instance consistently uses more CPU than its baseline allocation, AWS may throttle the instance to the baseline level to prevent excessive charges. This is likely what you're experiencing after 24 hours.

4. Workload assessment: Even though your workload remains the same, it may be too demanding for a t2.micro instance over extended periods. The instance might not be able to sustain the required performance level continuously.

5. Cost considerations: While unlimited mode allows you to burst above the baseline, it's not designed for constant high CPU usage. If your workload consistently requires high CPU, it may be more cost-effective to use a larger instance type or a different instance family that better suits your needs.

To address this issue, you could:

• Monitor your CPU utilization and credit balance closely
• Consider upgrading to a larger instance type if your workload consistently requires higher performance
• Optimize your application to reduce CPU usage if possible
• Evaluate if a different instance family might be more suitable for your constant high-CPU workload

Remember, unlimited mode is designed to handle temporary spikes in CPU usage, not to provide consistently high performance beyond the instance's baseline capabilities.
Sources
Unlimited mode for burstable performance instances - Amazon Elastic Compute Cloud
Problem with ec2 | AWS re:Post
EC2 Ubuntu T2.micro seems to be maxing CPU during application installation | AWS re:Post