Architecting Modern Java EE Applications

Emitting metrics

Metrics are usually not persisted in the application but in another system that is part of the environment, such as external monitoring solutions. This simplifies the implementation of metrics; the enterprise application keeps the information in memory and emits the specified metrics. External monitoring solutions scrape and process these metrics.

There are several techniques that can be used to emit and collect metrics. For example, measures can be formatted into custom JSON strings and exposed via HTTP endpoints.

A monitoring solution that is part of the Cloud Native Computing Foundation, and, as of today, has huge momentum, is Prometheus. Prometheus is a monitoring and alerting technology that scrapes, efficiently stores, ...