SmallRye Fault Tolerance

package org.acme.microprofile.faulttolerance;

public class Coffee {

    public Integer id;
    public String name;
    public String countryOfOrigin;
    public Integer price;

    public Coffee() {
    }

    public Coffee(Integer id, String name, String countryOfOrigin, Integer price) {
        this.id = id;
        this.name = name;
        this.countryOfOrigin = countryOfOrigin;
        this.price = price;
    }
}

package org.acme.microprofile.faulttolerance;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import jakarta.enterprise.context.ApplicationScoped;

@ApplicationScoped
public class CoffeeRepositoryService {

    private Map<Integer, Coffee> coffeeList = new HashMap<>();

    public CoffeeRepositoryService() {
        coffeeList.put(1, new Coffee(1, "Fernandez Espresso", "Colombia", 23));
        coffeeList.put(2, new Coffee(2, "La Scala Whole Beans", "Bolivia", 18));
        coffeeList.put(3, new Coffee(3, "Dak Lak Filter", "Vietnam", 25));
    }

    public List<Coffee> getAllCoffees() {
        return new ArrayList<>(coffeeList.values());
    }

    public Coffee getCoffeeById(Integer id) {
        return coffeeList.get(id);
    }

    public List<Coffee> getRecommendations(Integer id) {
        if (id == null) {
            return Collections.emptyList();
        }
        return coffeeList.values().stream()
                .filter(coffee -> !id.equals(coffee.id))
                .limit(2)
                .collect(Collectors.toList());
    }
}

package org.acme.microprofile.faulttolerance;

import java.util.List;
import java.util.Random;
import java.util.concurrent.atomic.AtomicLong;
import jakarta.inject.Inject;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;

import org.jboss.logging.Logger;

@Path("/coffee")
public class CoffeeResource {

    private static final Logger LOGGER = Logger.getLogger(CoffeeResource.class);

    @Inject
    CoffeeRepositoryService coffeeRepository;

    private AtomicLong counter = new AtomicLong(0);

    @GET
    public List<Coffee> coffees() {
        final Long invocationNumber = counter.getAndIncrement();

        maybeFail(String.format("CoffeeResource#coffees() invocation #%d failed", invocationNumber));

        LOGGER.infof("CoffeeResource#coffees() invocation #%d returning successfully", invocationNumber);
        return coffeeRepository.getAllCoffees();
    }

    private void maybeFail(String failureLogMessage) {
        if (new Random().nextBoolean()) {
            LOGGER.error(failureLogMessage);
            throw new RuntimeException("Resource failure.");
        }
    }
}

import org.eclipse.microprofile.faulttolerance.Retry;
...

public class CoffeeResource {
    ...
    @GET
    @Retry(maxRetries = 4)
    public List<Coffee> coffees() {
        ...
    }
    ...
}

2019-03-06 12:17:41,725 INFO  [org.acm.fau.CoffeeResource] (XNIO-1 task-1) CoffeeResource#coffees() invocation #5 returning successfully
2019-03-06 12:17:44,187 INFO  [org.acm.fau.CoffeeResource] (XNIO-1 task-1) CoffeeResource#coffees() invocation #6 returning successfully
2019-03-06 12:17:45,166 ERROR [org.acm.fau.CoffeeResource] (XNIO-1 task-1) CoffeeResource#coffees() invocation #7 failed
2019-03-06 12:17:45,172 ERROR [org.acm.fau.CoffeeResource] (XNIO-1 task-1) CoffeeResource#coffees() invocation #8 failed
2019-03-06 12:17:45,176 INFO  [org.acm.fau.CoffeeResource] (XNIO-1 task-1) CoffeeResource#coffees() invocation #9 returning successfully

import org.eclipse.microprofile.faulttolerance.Timeout;
...
public class CoffeeResource {
    ...
    @GET
    @Path("/{id}/recommendations")
    @Timeout(250)
    public List<Coffee> recommendations(int id) {
        long started = System.currentTimeMillis();
        final long invocationNumber = counter.getAndIncrement();

        try {
            randomDelay();
            LOGGER.infof("CoffeeResource#recommendations() invocation #%d returning successfully", invocationNumber);
            return coffeeRepository.getRecommendations(id);
        } catch (InterruptedException e) {
            LOGGER.errorf("CoffeeResource#recommendations() invocation #%d timed out after %d ms",
                    invocationNumber, System.currentTimeMillis() - started);
            return null;
        }
    }

    private void randomDelay() throws InterruptedException {
        Thread.sleep(new Random().nextInt(500));
    }
}

import java.util.Collections;
import org.eclipse.microprofile.faulttolerance.Fallback;

...
public class CoffeeResource {
    ...
    @Fallback(fallbackMethod = "fallbackRecommendations")
    public List<Coffee> recommendations(int id) {
        ...
    }

    public List<Coffee> fallbackRecommendations(int id) {
        LOGGER.info("Falling back to RecommendationResource#fallbackRecommendations()");
        // safe bet, return something that everybody likes
        return Collections.singletonList(coffeeRepository.getCoffeeById(1));
    }
    ...
}

2020-01-09 13:21:34,250 INFO  [org.acm.fau.CoffeeResource] (executor-thread-1) CoffeeResource#recommendations() invocation #1 returning successfully
2020-01-09 13:21:36,354 ERROR [org.acm.fau.CoffeeResource] (executor-thread-1) CoffeeResource#recommendations() invocation #2 timed out after 250 ms
2020-01-09 13:21:36,355 INFO  [org.acm.fau.CoffeeResource] (executor-thread-1) Falling back to RecommendationResource#fallbackRecommendations()

import java.util.concurrent.atomic.AtomicLong;
import org.eclipse.microprofile.faulttolerance.CircuitBreaker;
...

public class CoffeeRepositoryService {
    ...

    private AtomicLong counter = new AtomicLong(0);

    @CircuitBreaker(requestVolumeThreshold = 4)
    public Integer getAvailability(Coffee coffee) {
        maybeFail();
        return new Random().nextInt(30);
    }

    private void maybeFail() {
        // introduce some artificial failures
        final Long invocationNumber = counter.getAndIncrement();
        if (invocationNumber % 4 > 1) { // alternate 2 successful and 2 failing invocations
            throw new RuntimeException("Service failed.");
        }
    }
}

public class CoffeeResource {
    ...
    @Path("/{id}/availability")
    @GET
    public Response availability(int id) {
        final Long invocationNumber = counter.getAndIncrement();

        Coffee coffee = coffeeRepository.getCoffeeById(id);
        // check that coffee with given id exists, return 404 if not
        if (coffee == null) {
            return Response.status(Response.Status.NOT_FOUND).build();
        }

        try {
            Integer availability = coffeeRepository.getAvailability(coffee);
            LOGGER.infof("CoffeeResource#availability() invocation #%d returning successfully", invocationNumber);
            return Response.ok(availability).build();
        } catch (RuntimeException e) {
            String message = e.getClass().getSimpleName() + ": " + e.getMessage();
            LOGGER.errorf("CoffeeResource#availability() invocation #%d failed: %s", invocationNumber, message);
            return Response.status(Response.Status.INTERNAL_SERVER_ERROR)
                    .entity(message)
                    .type(MediaType.TEXT_PLAIN_TYPE)
                    .build();
        }
    }
    ...
}

import java.time.temporal.ChronoUnit;
import io.smallrye.faulttolerance.api.RateLimit;

...
public class CoffeeResource {
    ...
    @GET
    @RateLimit(value = 2, window = 10, windowUnit = ChronoUnit.SECONDS)
    public List<Coffee> coffees() {
        ...
    }
    ...
}

INFO  [org.acm.mic.fau.CoffeeResource] (executor-thread-1) CoffeeResource#coffees() invocation #1 returning successfully
ERROR [io.qua.ver.htt.run.QuarkusErrorHandler] (executor-thread-1) HTTP Request to /coffee failed, error id: d3e59090-fd45-4c67-844e-80a8f7fa6ee0-4: io.smallrye.faulttolerance.api.RateLimitException: org.acme.microprofile.faulttolerance.CoffeeResource#coffees rate limit exceeded
        at io.smallrye.faulttolerance.core.rate.limit.RateLimit.doApply(RateLimit.java:58)
        at io.smallrye.faulttolerance.core.rate.limit.RateLimit.apply(RateLimit.java:44)
        at io.smallrye.faulttolerance.FaultToleranceInterceptor.syncFlow(FaultToleranceInterceptor.java:255)
        at io.smallrye.faulttolerance.FaultToleranceInterceptor.intercept(FaultToleranceInterceptor.java:182)
        at io.smallrye.faulttolerance.FaultToleranceInterceptor_Bean.intercept(Unknown Source)
        at io.quarkus.arc.impl.InterceptorInvocation.invoke(InterceptorInvocation.java:42)
        at io.quarkus.arc.impl.AroundInvokeInvocationContext.perform(AroundInvokeInvocationContext.java:30)
        at io.quarkus.arc.impl.InvocationContexts.performAroundInvoke(InvocationContexts.java:27)
        at org.acme.microprofile.faulttolerance.CoffeeResource_Subclass.coffees(Unknown Source)
        at org.acme.microprofile.faulttolerance.CoffeeResource$quarkusrestinvoker$coffees_73d7590ab944adfa130e4ad57c30282f825b2d18.invoke(Unknown Source)
        at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
        at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:141)
        at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
        at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:599)
        at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2516)
        at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2495)
        at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1521)
        at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
        at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:1583)

package org.acme;

import org.eclipse.microprofile.faulttolerance.Retry;
...

public class CoffeeResource {
    ...
    @GET
    @Retry(maxRetries = 4)
    public List<Coffee> coffees() {
        ...
    }
    ...
}

quarkus.fault-tolerance."org.acme.CoffeeResource/coffees".retry.max-retries=6

# alternatively, a specification-defined property can be used
org.acme.CoffeeResource/coffees/Retry/maxRetries=6