EC2 instance metrics which is very important to get the alerts using cloudwatch

Monitoring your EC2 instances using Amazon CloudWatch is essential for maintaining the performance, reliability, and availability of your applications. Here are some of the most important EC2 instance metrics that you should consider setting up CloudWatch alarms for:

Key EC2 Instance Metrics for Monitoring and Alerts

1. CPU Utilization (CPUUtilization)
   • Description: Measures the percentage of allocated EC2 compute units that are currently in use.
   • Importance: High CPU utilization can indicate that the instance is under heavy load, while low utilization may suggest underutilization.
   • Suggested Alarms:
     • High CPU Utilization: Alert when the CPU utilization exceeds a threshold (e.g., 80%) for a sustained period.
     • Low CPU Utilization: Alert when the CPU utilization is below a threshold (e.g., 5%) for a sustained period.
2. Disk Read Operations (DiskReadOps)
   • Description: The number of completed read operations from all instance store volumes available to the instance.
   • Importance: High read operations can indicate intensive disk usage, potentially leading to performance bottlenecks.
   • Suggested Alarms: Alert when the number of read operations exceeds a predefined threshold.
3. Disk Write Operations (DiskWriteOps)
   • Description: The number of completed write operations to all instance store volumes available to the instance.
   • Importance: High write operations can indicate intensive disk usage, potentially leading to performance bottlenecks.
   • Suggested Alarms: Alert when the number of write operations exceeds a predefined threshold.
4. Disk Read Bytes (DiskReadBytes)
   • Description: The number of bytes read from all instance store volumes available to the instance.
   • Importance: Indicates the volume of data being read, useful for identifying excessive read operations.
   • Suggested Alarms: Alert when the read bytes exceed a predefined threshold.
5. Disk Write Bytes (DiskWriteBytes)
   • Description: The number of bytes written to all instance store volumes available to the instance.
   • Importance: Indicates the volume of data being written, useful for identifying excessive write operations.
   • Suggested Alarms: Alert when the write bytes exceed a predefined threshold.
6. Network In (NetworkIn)
   • Description: The number of bytes received on all network interfaces by the instance.
   • Importance: Monitoring inbound traffic can help identify potential issues like DDoS attacks or abnormal traffic patterns.
   • Suggested Alarms: Alert when the inbound traffic exceeds a predefined threshold.
7. Network Out (NetworkOut)
   • Description: The number of bytes sent out on all network interfaces by the instance.
   • Importance: Monitoring outbound traffic can help identify potential issues like data exfiltration or abnormal traffic patterns.
   • Suggested Alarms: Alert when the outbound traffic exceeds a predefined threshold.
8. Status Check Failed (Instance) (StatusCheckFailed_Instance)
   • Description: Reports whether the instance has passed the EC2 instance status checks.
   • Importance: Indicates overall health of the instance. A failure can mean issues with hardware or software on the instance.
   • Suggested Alarms: Alert immediately when any instance status check fails.
9. Status Check Failed (System) (StatusCheckFailed_System)
   • Description: Reports whether the instance has passed the EC2 system status checks.
   • Importance: Indicates underlying hardware or network issues. A failure can mean issues with the physical host or network.
   • Suggested Alarms: Alert immediately when any system status check fails.
10. Memory Utilization
    • Description: Measures the percentage of memory in use.
    • Importance: High memory utilization can lead to swapping and degraded performance.
    • Suggested Alarms: Alert when memory utilization exceeds a threshold (e.g., 80%).
11. Disk Space Utilization
    • Description: Measures the amount of disk space in use.
    • Importance: High disk space utilization can lead to disk full issues and degraded performance.
    • Suggested Alarms: Alert when disk space utilization exceeds a threshold (e.g., 80%).

Setting Up Alarms in CloudWatch

1. Navigate to CloudWatch Console:
   • Go to the Amazon CloudWatch console.
2. Create an Alarm:
   • Click on Alarms in the left navigation pane.
   • Click Create alarm.
3. Select a Metric:
   • Click Select metric.
   • Choose EC2 metrics.
   • Navigate to the relevant metrics (e.g., CPUUtilization, StatusCheckFailed_Instance, etc.).
   • Select the metric for your desired EC2 instance.
4. Configure Alarm Conditions:
   • Specify the threshold type (Static or Anomaly detection).
   • Set the condition (e.g., greater than 80% for CPU utilization).
   • Set the evaluation period (e.g., 5 minutes).
5. Add Notifications:
   • Under the Notification section, click Add notification.
   • Select an existing SNS topic or create a new one to receive notifications.
   • Define notification actions (e.g., send an email, SMS, or trigger a Lambda function).
6. Name and Review:
   • Give the alarm a meaningful name and description.
   • Review the configuration and click Create alarm.