SmallRye Fault Tolerance provides support for MicroProfile Metrics and Micrometer. Alternatively, metrics may be completely disabled at the integration level.

As usual, this integration is based on CDI, so an integrator must select one of the following classes and add it to the set of types scanned during CDI bean discovery:

  • io.smallrye.faulttolerance.metrics.MicroProfileMetricsProvider

  • io.smallrye.faulttolerance.metrics.MicrometerProvider

  • io.smallrye.faulttolerance.metrics.NoopProvider

All these classes implement an internal interface MetricsProvider. This interface, together with an internal core interface MetricsRecorder, is used by the rest of SmallRye Fault Tolerance to interact with the metrics system.

Only the names of the classes listed above are treated as public. That is, the classes should be treated as opaque, no guarantees about their internals are made.

The possibility to choose a metrics implementation is currently mainly provided for Quarkus. The CDI Portable Extension present in SmallRye Fault Tolerance always assumes MicroProfile Metrics are required.

Metrics providers have additional requirements, as described below.

MicroProfile Metrics

If MicroProfile Metrics are used, the integrator must ensure that the following artifacts are present:

  • org.eclipse.microprofile.metrics:microprofile-metrics-api;

  • some implementation of MicroProfile Metrics.

As mentioned above, when an integrator relies on the CDI Portable Extension provided by SmallRye Fault Tolerance, this is currently the default and only option. Therefore, presence of MicroProfile Metrics is mandatory for those integrators.


If Micrometer is used, the integrator must ensure that the following artifact is present:

  • io.micrometer:micrometer-core.


If the "noop" provider is used, metrics are completely disabled and the MP_Fault_Tolerance_Metrics_Enabled configuration property is ignored at runtime.

No metrics API and implementation is required in this case.