Log data is sent from various sources like EC2 instances, Lambda functions, CloudTrail, or custom applications to CloudWatch Logs.
AWS services like EC2 and Lambda have native integrations with CloudWatch Logs, but you can also use the CloudWatch Logs Agent to send logs from your on-premises servers or applications to CloudWatch Logs.
Log Group and Log Stream Creation:
Once the logs are received, CloudWatch Logs organizes them into log groups and log streams.
You can configure how log groups and log streams are named and how long logs are retained.
Storage and Retention:
Logs are stored in CloudWatch Logs, and you can configure retention policies for each log group. Logs can be retained for days, months, or indefinitely.
Analyzing Logs with CloudWatch Logs Insights:
You can use Logs Insights to query the log data for specific events or patterns. For example, you can search for error codes, request latency, or user activities.
CloudWatch Logs Insights offers a query language that allows for aggregations (e.g., counting occurrences), sorting, and filtering to quickly identify issues.
Log Monitoring and Alerts:
You can create metric filters that monitor specific patterns in the log data (e.g., error messages, warnings).
If a defined pattern is detected, CloudWatch can trigger alarms to notify you or take actions (e.g., send a notification via SNS or invoke a Lambda function).
Visualization and Dashboards:
CloudWatch allows you to create custom dashboards that include visualizations of your log data, making it easy to monitor log trends and spot issues at a glance.
