@Override
public void bindTo(MeterRegistry registry) {
    ClassLoadingMXBean classLoadingBean = ManagementFactory.getClassLoadingMXBean();

    Gauge.builder("jvm.classes.loaded", classLoadingBean, ClassLoadingMXBean::getLoadedClassCount)
            .tags(tags)
            .description("The number of classes that are currently loaded in the Java virtual machine")
            .baseUnit(BaseUnits.CLASSES)
            .register(registry);

    FunctionCounter.builder("jvm.classes.unloaded", classLoadingBean, ClassLoadingMXBean::getUnloadedClassCount)
            .tags(tags)
            .description("The total number of classes unloaded since the Java virtual machine has started execution")
            .baseUnit(BaseUnits.CLASSES)
            .register(registry);
}
 

@Test
void reportExpectedGeneralMetrics() {
    MeterRegistry registry = new SimpleMeterRegistry();
    metrics.bindTo(registry);

    verifyCommonCacheMetrics(registry, metrics);

    FunctionCounter evictionWeight = fetch(registry, "cache.eviction.weight").functionCounter();
    CacheStats stats = cache.stats();
    assertThat(evictionWeight.count()).isEqualTo(stats.evictionWeight());

    // specific to LoadingCache instance
    TimeGauge loadDuration = fetch(registry, "cache.load.duration").timeGauge();
    assertThat(loadDuration.value()).isEqualTo(stats.totalLoadTime());

    FunctionCounter successfulLoad = fetch(registry, "cache.load", Tags.of("result", "success")).functionCounter();
    assertThat(successfulLoad.count()).isEqualTo(stats.loadSuccessCount());

    FunctionCounter failedLoad = fetch(registry, "cache.load", Tags.of("result", "failure")).functionCounter();
    assertThat(failedLoad.count()).isEqualTo(stats.loadFailureCount());
}
 

public static void main(String[] args) {
    MeterRegistry registry = SampleConfig.myMonitoringSystem();

    AtomicInteger n = new AtomicInteger(0);

    FunctionCounter.builder("my.fcounter", n, AtomicInteger::get)
        .baseUnit("happiness")
        .description("A counter derived from a monotonically increasing value")
        .register(registry);

    Counter counter = Counter.builder("my.counter")
        .baseUnit("happiness")
        .description("A normal counter")
        .register(registry);

    Flux.interval(Duration.ofMillis(10))
        .doOnEach(i -> {
            n.incrementAndGet();
            counter.increment();
        })
        .blockLast();
}
 

@Test
@Parameters(method = "metricsSchedulers")
   public void shouldReportExecutorMetrics(Supplier<Scheduler> schedulerSupplier, String type) {
	Scheduler scheduler = afterTest.autoDispose(schedulerSupplier.get());
	final int taskCount = 3;

	for (int i = 0; i < taskCount; i++) {
		scheduler.schedule(() -> {
		});
	}

	Collection<FunctionCounter> counters = simpleMeterRegistry
			.find("executor.completed")
			.tag(TAG_SCHEDULER_ID, scheduler.toString())
			.functionCounters();

	// Use Awaitility because "count" is reported "eventually"
	await().atMost(5, TimeUnit.SECONDS).untilAsserted(() -> {
		assertThat(counters.stream()
		                   .mapToDouble(FunctionCounter::count)
		                   .sum())
				.isEqualTo(taskCount);
	});
   }
 

@Test
public void shouldAddMetricsForANewlyCreatedRetry() {
    Retry newRetry = retryRegistry.retry("backendB");

    assertThat(taggedRetryMetricsPublisher.meterIdMap).containsKeys("backendA", "backendB");
    assertThat(taggedRetryMetricsPublisher.meterIdMap.get("backendA")).hasSize(4);
    assertThat(taggedRetryMetricsPublisher.meterIdMap.get("backendB")).hasSize(4);

    List<Meter> meters = meterRegistry.getMeters();
    assertThat(meters).hasSize(8);

    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithoutRetry = MetricsTestHelper
        .findMeterByKindAndNameTags(counters, "successful_without_retry", newRetry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(newRetry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void shouldReplaceMetrics() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS).functionCounters();
    Optional<FunctionCounter> successfulWithoutRetry = MetricsTestHelper.findMeterByKindAndNameTags(counters,
        "successful_without_retry", retry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());

    Retry newRetry = Retry.of(retry.getName(), RetryConfig.custom().maxAttempts(1).build());

    retryRegistry.replace(retry.getName(), newRetry);

    counters = meterRegistry.get(DEFAULT_RETRY_CALLS).functionCounters();
    successfulWithoutRetry = MetricsTestHelper
        .findMeterByKindAndNameTags(counters, "successful_without_retry",
        newRetry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(newRetry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void shouldAddMetricsForANewlyCreatedRetry() {
    Retry newRetry = retryRegistry.retry("backendB");

    assertThat(taggedRetryMetrics.meterIdMap).containsKeys("backendA", "backendB");
    assertThat(taggedRetryMetrics.meterIdMap.get("backendA")).hasSize(4);
    assertThat(taggedRetryMetrics.meterIdMap.get("backendB")).hasSize(4);

    List<Meter> meters = meterRegistry.getMeters();
    assertThat(meters).hasSize(8);

    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithoutRetry = findMeterByKindAndNameTags(counters,
        "successful_without_retry", newRetry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(newRetry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void shouldReplaceMetrics() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();
    Optional<FunctionCounter> successfulWithoutRetry = findMeterByKindAndNameTags(counters,
        "successful_without_retry", retry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());

    Retry newRetry = Retry.of(retry.getName(), RetryConfig.custom().maxAttempts(1).build());

    retryRegistry.replace(retry.getName(), newRetry);

    counters = meterRegistry.get(DEFAULT_RETRY_CALLS).functionCounters();
    successfulWithoutRetry = findMeterByKindAndNameTags(counters, "successful_without_retry",
        newRetry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(newRetry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

/**
 * Build and register a typed meter.
 *
 * @return Optional type of {@link Meter}
 */
public Optional<Meter> build() {
    if (!isValid()) {
        return Optional.empty();
    }

    if (StringUtils.isEmpty(name)) {
        name = kafkaMetric.metricName().name();
    }

    KafkaMetricMeterType kafkaMetricMeterType = kafkaMetricMeterTypeRegistry.lookup(this.name);

    if (kafkaMetricMeterType.getMeterType() == MeterType.GAUGE && this.kafkaMetric.metricValue() instanceof Double) {
        return Optional.of(Gauge.builder(getMetricName(), () -> (Double) kafkaMetric.metricValue())
                .tags(tagFunction.apply(kafkaMetric.metricName()))
                .description(kafkaMetricMeterType.getDescription())
                .baseUnit(kafkaMetricMeterType.getBaseUnit())
                .register(meterRegistry));
    } else if (kafkaMetricMeterType.getMeterType() == MeterType.FUNCTION_COUNTER && this.kafkaMetric.metricValue() instanceof Double) {
        return Optional.of(FunctionCounter.builder(getMetricName(), kafkaMetric, value -> (Double) value.metricValue())
                .tags(tagFunction.apply(kafkaMetric.metricName()))
                .description(kafkaMetricMeterType.getDescription())
                .baseUnit(kafkaMetricMeterType.getBaseUnit())
                .register(meterRegistry));
    } else if (kafkaMetricMeterType.getMeterType() == MeterType.TIME_GAUGE && this.kafkaMetric.metricValue() instanceof Double) {
        return Optional.of(TimeGauge.builder(getMetricName(), kafkaMetric, kafkaMetricMeterType.getTimeUnit(), value -> (Double) value.metricValue())
                .tags(tagFunction.apply(kafkaMetric.metricName()))
                .description(kafkaMetricMeterType.getDescription())
                .register(meterRegistry));
    }

    return Optional.empty();
}
 

private void monitor(MeterRegistry registry, ThreadPoolExecutor tp) {
    FunctionCounter.builder(name + ".completed", tp, ThreadPoolExecutor::getCompletedTaskCount).tags(tags)
        .description("The approximate total number of tasks that have completed execution").register(registry);

    Gauge.builder(name + ".active", tp, ThreadPoolExecutor::getActiveCount).tags(tags)
        .description("The approximate number of threads that are actively executing tasks").register(registry);

    Gauge.builder(name + ".queued", tp, tpRef -> tpRef.getQueue().size()).tags(tags)
        .description("The approximate number of threads that are queued for execution").register(registry);

    Gauge.builder(name + ".pool", tp, ThreadPoolExecutor::getPoolSize).tags(tags)
        .description("The current number of threads in the pool").register(registry);
}
 

private void monitor(String name, ScheduledThreadPoolExecutor tp, MeterRegistry meterRegistry, Iterable<Tag> tags) {
    FunctionCounter.builder(name + ".completed", tp, ScheduledThreadPoolExecutor::getCompletedTaskCount).tags(tags)
        .description("The approximate total number of tasks that have completed execution").register(meterRegistry);
    Gauge.builder(name + ".active", tp, ScheduledThreadPoolExecutor::getActiveCount).tags(tags)
        .description("The approximate number of threads that are actively executing tasks").register(meterRegistry);
    Gauge.builder(name + ".queued", tp, (tpRef) -> {
        return (double)tpRef.getQueue().size();
    }).tags(tags).description("The approximate number of threads that are queued for execution")
        .register(meterRegistry);
    Gauge.builder(name + ".pool", tp, ScheduledThreadPoolExecutor::getPoolSize).tags(tags)
        .description("The current number of threads in the pool").register(meterRegistry);
}
 

private void registerFunctionCounterForObject(MeterRegistry registry, ObjectName o, String jmxMetricName,
    Tags allTags, String description, @Nullable String baseUnit) {
    FunctionCounter
        .builder(METRIC_NAME_PREFIX + sanitize(jmxMetricName), mBeanServer,
            s -> safeDouble(() -> s.getAttribute(o, jmxMetricName)))
        .description(description).baseUnit(baseUnit).tags(allTags).register(registry);
}
 

@Override
public void bindTo(MeterRegistry registry) {
    CompilationMXBean compilationBean = ManagementFactory.getCompilationMXBean();
    if (compilationBean != null && compilationBean.isCompilationTimeMonitoringSupported()) {
        FunctionCounter.builder("jvm.compilation.time", compilationBean, CompilationMXBean::getTotalCompilationTime)
                .tags(Tags.concat(tags, "compiler", compilationBean.getName()))
                .description("The approximate accumulated elapsed time spent in compilation")
                .baseUnit(BaseUnits.MILLISECONDS)
                .register(registry);
    }
}
 

@Override
FunctionCounter registerNewMeter(MeterRegistry registry) {
    final T obj = ref.get();
    if (obj == null) {
        return null;
    }

    return FunctionCounter.builder(getId().getName(), obj, f)
        .tags(getId().getTagsAsIterable())
        .description(getId().getDescription())
        .baseUnit(getId().getBaseUnit())
        .register(registry);
}
 

@Test
void count() {
    AtomicInteger n = new AtomicInteger(1);
    FunctionCounter counter = registry.more().counter("my.counter", Tags.empty(), n);

    assertThat(counter).isInstanceOf(StepFunctionCounter.class);
    assertThat(counter.count()).isEqualTo(0);
    clock.add(config.step());
    assertThat(counter.count()).isEqualTo(1);
}
 

@Test
void reportExpectedMetrics() {
    MeterRegistry registry = new SimpleMeterRegistry();
    metrics.bindTo(registry);

    verifyCommonCacheMetrics(registry, metrics);

    // common metrics
    Gauge cacheSize = fetch(registry, "cache.size").gauge();
    assertThat(cacheSize.value()).isEqualTo(cache.size());

    FunctionCounter hitCount = fetch(registry, "cache.gets", Tags.of("result", "hit")).functionCounter();
    assertThat(hitCount.count()).isEqualTo(metrics.hitCount());

    FunctionCounter missCount = fetch(registry, "cache.gets", Tags.of("result", "miss")).functionCounter();
    assertThat(missCount.count()).isEqualTo(metrics.missCount().doubleValue());

    FunctionCounter cachePuts = fetch(registry, "cache.puts").functionCounter();
    assertThat(cachePuts.count()).isEqualTo(metrics.putCount());

    FunctionCounter cacheEviction = fetch(registry, "cache.evictions").functionCounter();
    assertThat(cacheEviction.count()).isEqualTo(metrics.evictionCount().doubleValue());

    CacheStats stats = cache.stats();
    TimeGauge loadDuration = fetch(registry, "cache.load.duration").timeGauge();
    assertThat(loadDuration.value()).isEqualTo(stats.totalLoadTime());

    FunctionCounter successfulLoad = fetch(registry, "cache.load", Tags.of("result", "success")).functionCounter();
    assertThat(successfulLoad.count()).isEqualTo(stats.loadSuccessCount());

    FunctionCounter failedLoad = fetch(registry, "cache.load", Tags.of("result", "failure")).functionCounter();
    assertThat(failedLoad.count()).isEqualTo(stats.loadExceptionCount());
}
 

@Test
void newFunctionCounterWhenCountingModeIsCumulativeShouldReturnCumulativeFunctionCounter() {
    SimpleMeterRegistry registry = createRegistry(CountingMode.CUMULATIVE);
    Meter.Id id = new Meter.Id("some.timer", Tags.empty(), null, null, Meter.Type.COUNTER);
    FunctionCounter functionCounter = registry.newFunctionCounter(id, null, (o) -> 0d);
    assertThat(functionCounter).isInstanceOf(CumulativeFunctionCounter.class);
}
 

@Test
void newFunctionCounterWhenCountingModeIsStepShouldReturnStepFunctionCounter() {
    SimpleMeterRegistry registry = createRegistry(CountingMode.STEP);
    Meter.Id id = new Meter.Id("some.timer", Tags.empty(), null, null, Meter.Type.COUNTER);
    FunctionCounter functionCounter = registry.newFunctionCounter(id, null, (o) -> 0d);
    assertThat(functionCounter).isInstanceOf(StepFunctionCounter.class);
}
 

@Test
void writeFunctionCounterShouldDropInfiniteValues() {
    FunctionCounter counter = FunctionCounter.builder("myCounter", Double.POSITIVE_INFINITY, Number::doubleValue).register(meterRegistry);
    clock.add(config.step());
    assertThat(meterRegistry.writeFunctionCounter(counter).isPresent()).isFalse();

    counter = FunctionCounter.builder("myCounter", Double.NEGATIVE_INFINITY, Number::doubleValue).register(meterRegistry);
    clock.add(config.step());
    assertThat(meterRegistry.writeFunctionCounter(counter).isPresent()).isFalse();
}
 

@Test
void writeFunctionCounterShouldDropInfiniteValues() {
    FunctionCounter counter = FunctionCounter.builder("myCounter", Double.POSITIVE_INFINITY, Number::doubleValue).register(meterRegistry);
    clock.add(config.step());
    assertThat(meterRegistry.writeFunctionCounter(counter)).isEmpty();

    counter = FunctionCounter.builder("myCounter", Double.NEGATIVE_INFINITY, Number::doubleValue).register(meterRegistry);
    clock.add(config.step());
    assertThat(meterRegistry.writeFunctionCounter(counter)).isEmpty();
}
 

@Test
@DirtiesContext(methodMode = DirtiesContext.MethodMode.BEFORE_METHOD)
public void whenGettingBooksFromCacheThenReturnCorrectStatistics() {
    bookService.findAll();
    bookService.findAll();
    bookService.findAll();

    bookService.findByTitle("Spring Boot in Action");
    bookService.findByTitle("Spring Boot in Action");
    bookService.findByTitle("Kotlin");
    bookService.findByTitle("Kotlin");
    bookService.findByTitle("Kotlin");

    Cache books = cacheManager.getCache("books");

    Tags expectedTag = Tags.of("app", "test");
    MeterBinder metrics = provider.getMeterBinder(books, expectedTag);

    MeterRegistry registry = new SimpleMeterRegistry();
    metrics.bindTo(registry);

    FunctionCounter hits = registry.get("cache.gets").tags(expectedTag).tag("result", "hit").functionCounter();
    FunctionCounter misses = registry.get("cache.gets").tags(expectedTag).tag("result", "miss").functionCounter();

    assertThat(hits.count()).isEqualTo(5);
    assertThat(misses.count()).isEqualTo(3);

    bookService.findAll();
    bookService.findByTitle("Kotlin");

    assertThat(hits.count()).isEqualTo(7);
    assertThat(misses.count()).isEqualTo(3);
}
 

@Test
public void whenMemcachedCacheManagerBeanThenCacheStatisticsLoaded() {
    loadContext(CacheWithMemcachedCacheManagerConfiguration.class);

    CacheMeterBinderProvider provider = this.context.getBean(
            "memcachedCacheMeterBinderProvider", CacheMeterBinderProvider.class);

    assertThat(provider).isNotNull();

    CacheManager cacheManager = this.context.getBean(CacheManager.class);
    Cache books = cacheManager.getCache("books");

    MeterBinder metrics = provider.getMeterBinder(books, expectedTag);

    MeterRegistry registry = new SimpleMeterRegistry();
    metrics.bindTo(registry);

    FunctionCounter hits = registry.get("cache.gets").tags(expectedTag).tag("result", "hit").functionCounter();
    FunctionCounter misses = registry.get("cache.gets").tags(expectedTag).tag("result", "miss").functionCounter();
    FunctionCounter puts = registry.get("cache.puts").tags(expectedTag).functionCounter();
    double availableServersCount = registry.get("available_servers_count").gauge().value();

    assertThat(hits.count()).isEqualTo(0);
    assertThat(misses.count()).isEqualTo(0);
    assertThat(puts.count()).isEqualTo(0);
    assertThat(availableServersCount).isEqualTo(1.0);

    getCacheKeyValues(books, "a", "b", "b", "c", "d", "c", "a", "a", "a", "d");

    assertThat(hits.count()).isEqualTo(6);
    assertThat(misses.count()).isEqualTo(4);
    assertThat(puts.count()).isEqualTo(0);
    assertThat(availableServersCount).isEqualTo(1.0);
}
 

private void registerMetrics(MeterRegistry meterRegistry, Retry retry, List<Tag> customTags) {
    // Remove previous meters before register
    removeMetrics(meterRegistry, retry.getName());

    Set<Meter.Id> idSet = new HashSet<>();
    idSet.add(FunctionCounter.builder(names.getCallsMetricName(), retry,
        rt -> rt.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt())
        .description("The number of successful calls without a retry attempt")
        .tag(TagNames.NAME, retry.getName())
        .tag(TagNames.KIND, "successful_without_retry")
        .tags(customTags)
        .register(meterRegistry).getId());
    idSet.add(FunctionCounter.builder(names.getCallsMetricName(), retry,
        rt -> rt.getMetrics().getNumberOfSuccessfulCallsWithRetryAttempt())
        .description("The number of successful calls after a retry attempt")
        .tag(TagNames.NAME, retry.getName())
        .tag(TagNames.KIND, "successful_with_retry")
        .tags(customTags)
        .register(meterRegistry).getId());
    idSet.add(FunctionCounter.builder(names.getCallsMetricName(), retry,
        rt -> rt.getMetrics().getNumberOfFailedCallsWithoutRetryAttempt())
        .description("The number of failed calls without a retry attempt")
        .tag(TagNames.NAME, retry.getName())
        .tag(TagNames.KIND, "failed_without_retry")
        .tags(customTags)
        .register(meterRegistry).getId());
    idSet.add(FunctionCounter.builder(names.getCallsMetricName(), retry,
        rt -> rt.getMetrics().getNumberOfFailedCallsWithRetryAttempt())
        .description("The number of failed calls after a retry attempt")
        .tag(TagNames.NAME, retry.getName())
        .tag(TagNames.KIND, "failed_with_retry")
        .tags(customTags)
        .register(meterRegistry).getId());
    meterIdMap.put(retry.getName(), idSet);
}
 

@Test
public void successfulWithoutRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithoutRetry = findMeterByKindAndNameTags(
        counters, "successful_without_retry", retry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void successfulWithRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithRetry = MetricsTestHelper.findMeterByKindAndNameTags(counters,
        "successful_with_retry", retry.getName());
    assertThat(successfulWithRetry).isPresent();
    assertThat(successfulWithRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithRetryAttempt());
}
 

@Test
public void failedWithoutRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> failedWithoutRetry = MetricsTestHelper.findMeterByKindAndNameTags(
        counters, "failed_without_retry", retry.getName());
    assertThat(failedWithoutRetry).isPresent();
    assertThat(failedWithoutRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfFailedCallsWithoutRetryAttempt());
}
 

@Test
public void failedWithRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS).
        functionCounters();

    Optional<FunctionCounter> failedWithRetry = MetricsTestHelper
        .findMeterByKindAndNameTags(counters, "failed_with_retry",
        retry.getName());
    assertThat(failedWithRetry).isPresent();
    assertThat(failedWithRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfFailedCallsWithRetryAttempt());
}
 

@Test
public void testReplaceNewMeter() {
    Retry oldOne = Retry.of("backendC", RetryConfig.ofDefaults());
    // add meters of old
    taggedRetryMetricsPublisher.addMetrics(meterRegistry, oldOne);
    // one success call
    oldOne.executeRunnable(() -> { });

    assertThat(taggedRetryMetricsPublisher.meterIdMap).containsKeys("backendC");
    assertThat(taggedRetryMetricsPublisher.meterIdMap.get("backendC")).hasSize(4);
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();
    Optional<FunctionCounter> successfulWithoutRetry =
        findMeterByKindAndNameTags(counters, "successful_without_retry", oldOne.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(oldOne.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());


    Retry newOne = Retry.of("backendC", RetryConfig.ofDefaults());
    // add meters of old
    taggedRetryMetricsPublisher.addMetrics(meterRegistry, newOne);
    // three success call
    newOne.executeRunnable(() -> { });
    newOne.executeRunnable(() -> { });
    newOne.executeRunnable(() -> { });

    assertThat(taggedRetryMetricsPublisher.meterIdMap).containsKeys("backendC");
    assertThat(taggedRetryMetricsPublisher.meterIdMap.get("backendC")).hasSize(4);
    counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();
    successfulWithoutRetry =
        findMeterByKindAndNameTags(counters, "successful_without_retry", newOne.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(newOne.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void successfulWithoutRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithoutRetry = findMeterByKindAndNameTags(counters,
        "successful_without_retry", retry.getName());
    assertThat(successfulWithoutRetry).isPresent();
    assertThat(successfulWithoutRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithoutRetryAttempt());
}
 

@Test
public void successfulWithRetryCallsGaugeReportsCorrespondingValue() {
    Collection<FunctionCounter> counters = meterRegistry.get(DEFAULT_RETRY_CALLS)
        .functionCounters();

    Optional<FunctionCounter> successfulWithRetry = findMeterByKindAndNameTags(counters,
        "successful_with_retry", retry.getName());
    assertThat(successfulWithRetry).isPresent();
    assertThat(successfulWithRetry.get().count())
        .isEqualTo(retry.getMetrics().getNumberOfSuccessfulCallsWithRetryAttempt());
}