EC2 Namespace, EBS/ disk Metrics stopped reporting on Cloudwatch | June 21, 2025 9:30PM GMT

Hello @vibster-tradex

[Step 1]: Check AWS Service Health Dashboard The first step is to check the AWS Service Health Dashboard for any reported outages or maintenance activities that might have affected CloudWatch metrics collection. This can be done by visiting the AWS Management Console and navigating to the Health Dashboard. Look for any events that occurred around June 21, 2025, 9:30 PM GMT, specifically related to CloudWatch, EC2, or EBS in the region where the EC2 instance is located. If there was a known issue, this would explain the missing metrics.

[Step 2]: Verify CloudWatch Agent Configuration Connect to the EC2 instance via SSH (if possible) and check the status of the CloudWatch agent.

Check Agent Status:

sudo systemctl status amazon-cloudwatch-agent If the agent is not running, start it:

sudo systemctl start amazon-cloudwatch-agent If the agent fails to start, proceed to the next steps to examine the configuration and logs.

Check Agent Configuration File: The CloudWatch agent configuration file is typically located at /opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json. Examine this file to ensure it is correctly configured to collect the desired metrics. Pay close attention to the metrics_collected section and ensure that disk I/O metrics are included. A minimal configuration might look like this:

{ "agent": { "metrics_collection_interval": 60, "run_as_user": "cwagent" }, "metrics": { "append_dimensions": { "InstanceId": "${instance_id}" }, "metrics_collected": { "disk": { "measurement": [ "disk_free", "disk_total", "disk_used", "disk_used_percent" ], "metrics_collection_interval": 60, "resources": [ "" ] }, "diskio": { "measurement": [ "io_time", "read_bytes", "write_bytes", "reads", "writes" ], "metrics_collection_interval": 60, "resources": [ "" ] } } } } Reload Agent Configuration: After modifying the configuration file, reload the agent:

sudo /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c file:/opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json [Step 3]: Check IAM Role Permissions Verify that the IAM role associated with the EC2 instance has the necessary permissions to write metrics to CloudWatch. The role should include the CloudWatchAgentServerPolicy or a custom policy with equivalent permissions. Specifically, the policy should allow the cloudwatch:PutMetricData action.

Example IAM Policy:

{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "cloudwatch:PutMetricData", "cloudwatch:GetMetricData", "cloudwatch:GetMetricStatistics", "cloudwatch:ListMetrics", "cloudwatch:DescribeAlarms" ], "Resource": "" }, { "Effect": "Allow", "Action": [ "ec2:DescribeTags" ], "Resource": "" } ] } [Step 4]: Review CloudWatch Logs Examine the CloudWatch agent logs for any errors or warnings. The logs are typically located at /opt/aws/amazon-cloudwatch-agent/logs/amazon-cloudwatch-agent.log. Look for any messages indicating problems with metrics collection or delivery. Common issues include permission errors, configuration errors, or network connectivity problems.

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