Metric Filters for Security Events

Raw logs are rich but passive. A metric filter scans incoming log events in a log group, matches a pattern you define, and turns each match into a numeric data point in a CloudWatch metric. This bridges text logs and the metric world, where you can graph trends and, crucially, trigger alarms.

Security signals are often buried in ordinary logs: a failed login, an unauthorized API call, a console sign-in without MFA. A metric filter extracts exactly those lines and counts them. Once a security event is a metric, it becomes something you can watch and alert on automatically instead of hoping a human notices it scrolling by.