EC2 instance resource exhaustion.

EC2 instance resource exhaustion can occur when the resources (CPU, memory, disk space, etc.) allocated to an Amazon Elastic Compute Cloud (EC2) instance are fully utilized, leading to degraded performance or even complete unavailability of the instance. This can be caused by a variety of factors, and addressing it depends on identifying the specific resource that is exhausted. Here are some common causes and steps to address them:

1. CPU Exhaustion:
   • Cause: High CPU usage from processes or applications running on the instance.
   • Solution:
     • Identify the processes causing high CPU usage using monitoring tools like CloudWatch or system-level utilities like top.
     • Optimize or scale the application, or consider using a larger instance type with more CPU resources.
2. Memory Exhaustion:
   • Cause: The application or processes on the instance are using more memory than is available.
   • Solution:
     • Identify memory-intensive processes using monitoring tools or system utilities like top.
     • Consider optimizing the application's memory usage, adding more memory to the existing instance, or migrating to a larger instance type.
3. Disk Space Exhaustion:
   • Cause: The instance's disk is running out of space due to excessive data storage.
   • Solution:
     • Identify large or unnecessary files using tools like du or monitoring services.
     • Clear out unneeded files, resize the EBS volume, or consider archiving data to a different storage solution like Amazon S3.
4. Network Bandwidth Exhaustion:
   • Cause: The instance is generating or receiving more network traffic than its network capacity can handle.
   • Solution:
     • Analyze network traffic patterns using CloudWatch or network monitoring tools.
     • Consider using a larger instance type with higher network performance, or optimizing the application's network usage.
5. I/O (Input/Output) Operations Exhaustion:
   • Cause: The instance is performing too many read/write operations on its disk, leading to high I/O wait times.
   • Solution:
     • Monitor disk I/O using tools like iostat.
     • Optimize disk usage patterns, consider using provisioned IOPS (if using EBS volumes), or switch to a larger instance type with better I/O performance.
6. Application-Level Optimizations:
   • Depending on the specific application running on the instance, there may be optimizations that can be made within the application itself to reduce resource consumption.
7. Horizontal Scaling:
   • Consider using an Auto Scaling Group to automatically add or remove instances based on load. This can help distribute the load and prevent resource exhaustion.

Remember to always monitor your instances using tools like Amazon CloudWatch, and set up appropriate alarms to get notified when resources approach critical levels. Additionally, regular performance analysis and capacity planning are crucial to avoid resource exhaustion in the first place.