Java applications like Tomcat or Cassandra often rely on JMX for performance monitoring. However, extracting metrics from JMX can be challenging and time-consuming. Previously, system admins and developers used JConsole to view these metrics quickly but it had limitations such as not retaining historical data, limited graphing capabilities, and lack of alerting support. Datadog's newly released agent addresses these issues with an upgraded JMX connector called JMXFetch. This tool collects JMX metrics automatically and makes them available for analysis, alerting, and correlation within the Datadog platform. With Datadog, users can graph JMX metrics from specific hosts or aggregated metrics from tagged hosts, set alerts on individual or aggregated metrics, and correlate JMX metrics with events in other systems to understand their impact on application performance.