JAX-RS metrics

SmallRye Metrics 3.0 supports the optional JAX-RS metrics as defined in the specification. To enable collection of JAX-RS metrics for an application, it is necessary to apply two filters:

  • io.smallrye.metrics.jaxrs.JaxRsMetricsFilter - a JAX-RS ContainerRequestFilter

  • io.smallrye.metrics.jaxrs.JaxRsMetricsServletFilter - a servlet filter

The reason for using two filters is that unfortunately, JAX-RS specification does not require ContainerResponseFilter-s to be invoked when request handling ended in an unmapped exception. That’s why we need to use a servlet filter instead to be able to hook into the responses even in these cases.

If the target runtime does not support servlets, a different mechanism needs to be used that will be able to hook into JAX-RS responses and will mimic the functionality of JaxRsMetricsServletFilter.

At the moment, there is no general mechanism to register JAX-RS metrics eagerly at deployment time - metric for each JAX-RS method is registered as soon as that method is invoked.