CloudWatch Logs

• You can use CloudWatch Logs to monitor, store, and access your log files from EC2 instances, CloudTrail, Route 53, and other sources.

• CloudWatch Logs enables you to centralize the logs from all of your systems, applications, and AWS services that you use, in a single, highly scalable service.

• You can then easily view them, search them for specific error codes or patterns, filter them based on specific fields, or archive them securely for future analysis.

Log streams

• A log stream is a sequence of log events that share the same source.

Log groups

• A log group is a group of log streams that share the same settings, such as retention, monitoring, and access control.

• You define log groups and specify which streams to put into each group.

• There is no limit on the number of log streams that can belong to one log group.

Metric filters

• You can use metric filters to extract metric observations from ingested events and transform them to data points in a CloudWatch metric.

• Metric filters are assigned to log groups, and all of the filters assigned to a log group are applied to their log streams.

Retention settings

• Retention settings can be used to specify how long log events are kept in CloudWatch Logs.

• Retention settings are also assigned to log groups.

Logs Insights

• Logs Insights enables you to interactively search and analyse your log data in Amazon CloudWatch Logs.

• You can perform queries to help you more efficiently and effectively respond to operational issues.

• Logs Insights includes a purpose-built query language.