It is increasingly important to build fault tolerant micro services. Fault tolerance is about leveraging different strategies to guide the execution and result of some logic. Retry policies, bulkheads, and circuit breakers are popular concepts in this area. They dictate whether and when executions should take place, and fallbacks offer an alternative result when an execution does not complete successfully.

Fault Tolerance provides developers with the following strategies for dealing with failure:

• Timeout: Define a maximum duration for execution

• Retry: Attempt execution again if it fails

• Bulkhead: Limit concurrent execution so that failures in that area can’t overload the whole system

• CircuitBreaker: Automatically fail fast when execution repeatedly fails

• Fallback: Provide an alternative solution when execution fails

Fault Tolerance provides an annotation for each strategy which can be placed on the methods of CDI beans. When an annotated method is called, the call is intercepted and the corresponding fault tolerance strategies are applied to the execution of that method.

For links to the latest maven artifacts, Javadoc and specification document, see the latest release.

Apply the retry and fallback strategies to doWork(). It will be executed up to two additional times if if throws an exception. If all executions throw an exception, doWorkFallback() will be called and the result of that returned instead.

From elsewhere, inject the FaultToleranceBean and call the method:

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