Fault Tolerance 6.2.0

Today, we announce the release of SmallRye Fault Tolerance 6.2.0.

As described in the previous announcement, this release marks the end of life of SmallRye Fault Tolerance 5. There will be no more releases in the 5.x stream. This also means there will be no more Java 8 support.

This release also upgrades to the Jakarta EE 10 dependencies.


Previously, the documentation contained numerous references to the MicroProfile Fault Tolerance specification, and all SmallRye Fault Tolerance improvements on top of the specification were described in a single, long, hard to read document.

In SmallRye Fault Tolerance 6.2.0, the documentation has been thoroughly restructured and revised. It should contain all the necessary information, so that you no longer have to refer to the specification for pretty basic stuff. The improvements on top of the specification are now placed in the same guide that describes the basic feature.

Overall, the documentation now contains more information and yet should be much easier to navigate and read. It is divided into 2 major sections:

  • How-to Guides: task-oriented guides that let you quickly start using some feature. They provide a short overview, but not many details.

  • References: detailed guides that let you understand some feature in depth. They also provide information about more advanced options or features.

There are 2 other sections (Integration, Internals), but those are not terribly useful for application developers.

Circuit breaker state metric

This release also adds one small feature: current state of circuit breakers is now exposed through metrics.

A new metric called ft.circuitbreaker.state.current is added. It has the following tags:

  • method: the fully qualified method name, like in all other fault tolerance metrics

  • state = [open|closed|halfOpen]: the circuit breaker state

This metric is a gauge with a value of 0 or 1. The value of 1 means that the circuit breaker currently is in given state, while 0 means that it is not.