Merge "Expose Prometheus metrics"

11 files changed, 204 insertions, 97 deletions

diff --git a/pom.xml b/pom.xml
index 621c5b2c..135d7350 100644
--- a/pom.xml
+++ b/pom.xml
@@ -577,8 +577,8 @@
             </dependency>
             <dependency>
                 <groupId>io.micrometer</groupId>
-                <artifactId>micrometer-registry-jmx</artifactId>
-                <version>1.0.5</version>
+                <artifactId>micrometer-registry-prometheus</artifactId>
+                <version>1.0.8</version>
             </dependency>
 
             <!-- Test dependencies -->
diff --git a/sources/hv-collector-ct/src/test/kotlin/org/onap/dcae/collectors/veshv/tests/fakes/metrics.kt b/sources/hv-collector-ct/src/test/kotlin/org/onap/dcae/collectors/veshv/tests/fakes/metrics.kt
index aa3fdc39..f3fc2381 100644
--- a/sources/hv-collector-ct/src/test/kotlin/org/onap/dcae/collectors/veshv/tests/fakes/metrics.kt
+++ b/sources/hv-collector-ct/src/test/kotlin/org/onap/dcae/collectors/veshv/tests/fakes/metrics.kt
@@ -25,7 +25,7 @@ import org.onap.dcae.collectors.veshv.boundary.Metrics
  * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
  * @since June 2018
  */
-class FakeMetrics: Metrics {
+class FakeMetrics : Metrics {
     override fun notifyBytesReceived(size: Int) {
     }
 
diff --git a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
index ac282008..aead71bb 100644
--- a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
+++ b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/factory/HealthCheckApiServer.kt
@@ -23,6 +23,7 @@ import arrow.effects.IO
 import io.netty.handler.codec.http.HttpResponseStatus
 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthDescription
 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthState
+import org.onap.dcae.collectors.veshv.healthcheck.ports.PrometheusMetricsProvider
 import org.onap.dcae.collectors.veshv.utils.NettyServerHandle
 import org.onap.dcae.collectors.veshv.utils.ServerHandle
 import org.onap.dcae.collectors.veshv.utils.logging.Logger
@@ -39,6 +40,7 @@ import java.util.concurrent.atomic.AtomicReference
  * @since August 2018
  */
 class HealthCheckApiServer(private val healthState: HealthState,
+                           private val monitoring: PrometheusMetricsProvider,
                            private val listenAddress: SocketAddress) {
 
     private val healthDescription: AtomicReference<HealthDescription> = AtomicReference(HealthDescription.STARTING)
@@ -50,6 +52,7 @@ class HealthCheckApiServer(private val healthState: HealthState,
                 .route { routes ->
                     routes.get("/health/ready", ::readinessHandler)
                     routes.get("/health/alive", ::livenessHandler)
+                    routes.get("/monitoring/prometheus", ::monitoringHandler)
                 }
         NettyServerHandle(ctx.bindNow())
     }
@@ -63,6 +66,10 @@ class HealthCheckApiServer(private val healthState: HealthState,
     private fun livenessHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
             resp.status(HttpResponseStatus.NOT_IMPLEMENTED).sendString(Mono.just("Not implemented yet"))
 
+
+    private fun monitoringHandler(_req: HttpServerRequest, resp: HttpServerResponse) =
+            resp.sendString(monitoring.lastStatus())
+
     companion object {
         private val logger = Logger(HealthCheckApiServer::class)
     }
diff --git a/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt
new file mode 100644
index 00000000..c5018759
--- /dev/null
+++ b/sources/hv-collector-health-check/src/main/kotlin/org/onap/dcae/collectors/veshv/healthcheck/ports/PrometheusMetricsProvider.kt
@@ -0,0 +1,30 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.healthcheck.ports
+
+import reactor.core.publisher.Mono
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since December 2018
+ */
+interface PrometheusMetricsProvider {
+    fun lastStatus(): Mono<String>
+}
diff --git a/sources/hv-collector-main/pom.xml b/sources/hv-collector-main/pom.xml
index a94d6346..9e124efd 100644
--- a/sources/hv-collector-main/pom.xml
+++ b/sources/hv-collector-main/pom.xml
@@ -135,7 +135,7 @@
         -->
         <dependency>
             <groupId>io.micrometer</groupId>
-            <artifactId>micrometer-registry-jmx</artifactId>
+            <artifactId>micrometer-registry-prometheus</artifactId>
         </dependency>
     </dependencies>
 
diff --git a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt
deleted file mode 100644
index 8a8b6d39..00000000
--- a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * ============LICENSE_START=======================================================
- * dcaegen2-collectors-veshv
- * ================================================================================
- * Copyright (C) 2018 NOKIA
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-package org.onap.dcae.collectors.veshv.main
-
-import arrow.syntax.function.memoize
-import io.micrometer.core.instrument.Clock
-import io.micrometer.core.instrument.Counter
-import io.micrometer.core.instrument.MeterRegistry
-import io.micrometer.jmx.JmxConfig
-import io.micrometer.jmx.JmxMeterRegistry
-import org.onap.dcae.collectors.veshv.boundary.Metrics
-
-/**
- * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
- * @since June 2018
- */
-class MicrometerMetrics(
-        private val registry: MeterRegistry = JmxMeterRegistry(JmxConfig.DEFAULT, Clock.SYSTEM)
-) : Metrics {
-
-    private val receivedBytes = registry.counter("data.received.bytes")
-    private val receivedMsgCount = registry.counter("messages.received.count")
-    private val receivedMsgBytes = registry.counter("messages.received.bytes")
-    private val sentCountTotal = registry.counter("messages.sent.count")
-
-    init {
-        registry.gauge("messages.processing.count", this) {
-            (receivedMsgCount.count() - sentCountTotal.count()).coerceAtLeast(0.0)
-        }
-    }
-
-    private val sentCount = { topic: String ->
-        registry.counter("messages.sent.count", "topic", topic)
-    }.memoize<String, Counter>()
-
-
-    override fun notifyBytesReceived(size: Int) {
-        receivedBytes.increment(size.toDouble())
-    }
-
-    override fun notifyMessageReceived(size: Int) {
-        receivedMsgCount.increment()
-        receivedMsgBytes.increment(size.toDouble())
-    }
-
-    override fun notifyMessageSent(topic: String) {
-        sentCountTotal.increment()
-        sentCount(topic).increment()
-    }
-}
diff --git a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerMetrics.kt b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerMetrics.kt
new file mode 100644
index 00000000..cf903591
--- /dev/null
+++ b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerMetrics.kt
@@ -0,0 +1,90 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.main.metrics
+
+import arrow.syntax.function.memoize
+import io.micrometer.core.instrument.Counter
+import io.micrometer.core.instrument.binder.jvm.ClassLoaderMetrics
+import io.micrometer.core.instrument.binder.jvm.JvmGcMetrics
+import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics
+import io.micrometer.core.instrument.binder.jvm.JvmThreadMetrics
+import io.micrometer.core.instrument.binder.system.ProcessorMetrics
+import io.micrometer.prometheus.PrometheusConfig
+import io.micrometer.prometheus.PrometheusMeterRegistry
+import org.onap.dcae.collectors.veshv.boundary.Metrics
+
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since June 2018
+ */
+class MicrometerMetrics internal constructor(
+        private val registry: PrometheusMeterRegistry = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)
+) : Metrics {
+
+    private val receivedBytes = registry.counter(name(DATA, RECEIVED, BYTES))
+    private val receivedMsgCount = registry.counter(name(MESSAGES, RECEIVED, COUNT))
+    private val receivedMsgBytes = registry.counter(name(MESSAGES, RECEIVED, BYTES))
+    private val sentCountTotal = registry.counter(name(MESSAGES, SENT, COUNT))
+
+    init {
+        registry.gauge(name(MESSAGES, PROCESSING, COUNT), this) {
+            (receivedMsgCount.count() - sentCountTotal.count()).coerceAtLeast(0.0)
+        }
+        ClassLoaderMetrics().bindTo(registry)
+        JvmMemoryMetrics().bindTo(registry)
+        JvmGcMetrics().bindTo(registry)
+        ProcessorMetrics().bindTo(registry)
+        JvmThreadMetrics().bindTo(registry)
+    }
+
+    private val sentCount = { topic: String ->
+        registry.counter("hvves.messages.sent.topic.count", "topic", topic)
+    }.memoize<String, Counter>()
+
+    val metricsProvider = MicrometerPrometheusMetricsProvider(registry)
+
+    override fun notifyBytesReceived(size: Int) {
+        receivedBytes.increment(size.toDouble())
+    }
+
+    override fun notifyMessageReceived(size: Int) {
+        receivedMsgCount.increment()
+        receivedMsgBytes.increment(size.toDouble())
+    }
+
+    override fun notifyMessageSent(topic: String) {
+        sentCountTotal.increment()
+        sentCount(topic).increment()
+    }
+
+    companion object {
+        val INSTANCE = MicrometerMetrics()
+        internal const val PREFIX = "hvves"
+        internal const val MESSAGES = "messages"
+        internal const val RECEIVED = "received"
+        internal const val BYTES = "bytes"
+        internal const val COUNT = "count"
+        internal const val DATA = "data"
+        internal const val SENT = "sent"
+        internal const val PROCESSING = "processing"
+        fun name(vararg name: String) = "$PREFIX.${name.joinToString(".")}"
+    }
+}
diff --git a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerPrometheusMetricsProvider.kt b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerPrometheusMetricsProvider.kt
new file mode 100644
index 00000000..2af8e38f
--- /dev/null
+++ b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/metrics/MicrometerPrometheusMetricsProvider.kt
@@ -0,0 +1,34 @@
+/*
+ * ============LICENSE_START=======================================================
+ * dcaegen2-collectors-veshv
+ * ================================================================================
+ * Copyright (C) 2018 NOKIA
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.dcae.collectors.veshv.main.metrics
+
+import io.micrometer.prometheus.PrometheusMeterRegistry
+import org.onap.dcae.collectors.veshv.healthcheck.ports.PrometheusMetricsProvider
+import reactor.core.publisher.Mono
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since December 2018
+ */
+class MicrometerPrometheusMetricsProvider(private val registry: PrometheusMeterRegistry) : PrometheusMetricsProvider {
+    override fun lastStatus(): Mono<String> = Mono.fromCallable {
+        registry.scrape()
+    }
+}
diff --git a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/HealthCheckServer.kt b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/HealthCheckServer.kt
index ae59da69..00123f1a 100644
--- a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/HealthCheckServer.kt
+++ b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/HealthCheckServer.kt
@@ -21,6 +21,7 @@ package org.onap.dcae.collectors.veshv.main.servers
 
 import org.onap.dcae.collectors.veshv.healthcheck.api.HealthState
 import org.onap.dcae.collectors.veshv.healthcheck.factory.HealthCheckApiServer
+import org.onap.dcae.collectors.veshv.main.metrics.MicrometerMetrics
 import org.onap.dcae.collectors.veshv.model.ServerConfiguration
 import org.onap.dcae.collectors.veshv.utils.ServerHandle
 
@@ -34,6 +35,7 @@ object HealthCheckServer : ServerStarter() {
     private fun createHealthCheckServer(config: ServerConfiguration) =
             HealthCheckApiServer(
                     HealthState.INSTANCE,
+                    MicrometerMetrics.INSTANCE.metricsProvider,
                     config.healthCheckApiListenAddress)
 
     override fun serverStartedMessage(handle: ServerHandle) =
diff --git a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/VesServer.kt b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/VesServer.kt
index d788c164..b35dc53d 100644
--- a/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/VesServer.kt
+++ b/sources/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/servers/VesServer.kt
@@ -24,7 +24,7 @@ import org.onap.dcae.collectors.veshv.boundary.Server
 import org.onap.dcae.collectors.veshv.factory.CollectorFactory
 import org.onap.dcae.collectors.veshv.factory.ServerFactory
 import org.onap.dcae.collectors.veshv.impl.adapters.AdapterFactory
-import org.onap.dcae.collectors.veshv.main.MicrometerMetrics
+import org.onap.dcae.collectors.veshv.main.metrics.MicrometerMetrics
 import org.onap.dcae.collectors.veshv.model.ServerConfiguration
 import org.onap.dcae.collectors.veshv.utils.ServerHandle
 
@@ -40,7 +40,7 @@ object VesServer : ServerStarter() {
         val collectorProvider = CollectorFactory(
                 AdapterFactory.consulConfigurationProvider(config.configurationProviderParams),
                 sink,
-                MicrometerMetrics(),
+                MicrometerMetrics.INSTANCE,
                 config.maximumPayloadSizeBytes
         ).createVesHvCollectorProvider()
 
diff --git a/sources/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt b/sources/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt
index a379933e..66326ddc 100644
--- a/sources/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt
+++ b/sources/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt
@@ -24,12 +24,17 @@ import io.micrometer.core.instrument.Counter
 import io.micrometer.core.instrument.Gauge
 import io.micrometer.core.instrument.search.RequiredSearch
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry
+import io.micrometer.prometheus.PrometheusConfig
+import io.micrometer.prometheus.PrometheusMeterRegistry
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.data.Percentage
 import org.jetbrains.spek.api.Spek
 import org.jetbrains.spek.api.dsl.describe
 import org.jetbrains.spek.api.dsl.it
 import org.jetbrains.spek.api.dsl.on
+import org.onap.dcae.collectors.veshv.healthcheck.ports.PrometheusMetricsProvider
+import org.onap.dcae.collectors.veshv.main.metrics.MicrometerMetrics
+import org.onap.dcae.collectors.veshv.main.metrics.MicrometerMetrics.Companion.PREFIX
 
 /**
  * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
@@ -37,11 +42,11 @@ import org.jetbrains.spek.api.dsl.on
  */
 object MicrometerMetricsTest : Spek({
     val doublePrecision = Percentage.withPercentage(0.5)
-    lateinit var registry: SimpleMeterRegistry
+    lateinit var registry: PrometheusMeterRegistry
     lateinit var cut: MicrometerMetrics
 
     beforeEachTest {
-        registry = SimpleMeterRegistry()
+        registry = PrometheusMeterRegistry(PrometheusConfig.DEFAULT)
         cut = MicrometerMetrics(registry)
     }
 
@@ -67,14 +72,17 @@ object MicrometerMetricsTest : Spek({
     fun verifyAllCountersAreUnchangedBut(vararg changedCounters: String) {
         registry.meters
                 .filter { it is Counter }
+                .map { it as Counter }
                 .filterNot { it.id.name in changedCounters }
-                .forEach { assertThat((it as Counter).count()).isCloseTo(0.0, doublePrecision) }
+                .forEach {
+                    assertThat(it.count()).describedAs(it.id.toString()).isCloseTo(0.0, doublePrecision)
+                }
     }
 
     describe("notifyBytesReceived") {
 
-        on("data.received.bytes counter") {
-            val counterName = "data.received.bytes"
+        on("$PREFIX.data.received.bytes counter") {
+            val counterName = "$PREFIX.data.received.bytes"
 
             it("should increment counter") {
                 val bytes = 128
@@ -93,8 +101,8 @@ object MicrometerMetricsTest : Spek({
     }
 
     describe("notifyMessageReceived") {
-        on("messages.received.count counter") {
-            val counterName = "messages.received.count"
+        on("$PREFIX.messages.received.count counter") {
+            val counterName = "$PREFIX.messages.received.count"
 
             it("should increment counter") {
                 cut.notifyMessageReceived(777)
@@ -105,8 +113,8 @@ object MicrometerMetricsTest : Spek({
             }
         }
 
-        on("messages.received.bytes counter") {
-            val counterName = "messages.received.bytes"
+        on("$PREFIX.messages.received.bytes counter") {
+            val counterName = "$PREFIX.messages.received.bytes"
 
             it("should increment counter") {
                 val bytes = 888
@@ -120,39 +128,42 @@ object MicrometerMetricsTest : Spek({
 
         it("should leave all other counters unchanged") {
             cut.notifyMessageReceived(128)
-            verifyAllCountersAreUnchangedBut("messages.received.count", "messages.received.bytes")
+            verifyAllCountersAreUnchangedBut("$PREFIX.messages.received.count", "$PREFIX.messages.received.bytes")
         }
     }
 
     describe("notifyMessageSent") {
-        val topicName = "dmaap_topic_name"
-        val counterName = "messages.sent.count"
+        val topicName1 = "PERF3GPP"
+        val topicName2 = "CALLTRACE"
 
-        on("$counterName counter") {
+        on("$PREFIX.messages.sent.count counter") {
+            val counterName = "$PREFIX.messages.sent.count"
 
             it("should increment counter") {
-                cut.notifyMessageSent(topicName)
+                cut.notifyMessageSent(topicName1)
 
                 verifyCounter(counterName) { counter ->
                     assertThat(counter.count()).isCloseTo(1.0, doublePrecision)
                 }
+                verifyAllCountersAreUnchangedBut(counterName, "$PREFIX.messages.sent.topic.count")
             }
         }
 
-        on("$counterName[topic=$topicName] counter") {
-
-            it("should increment counter") {
-                cut.notifyMessageSent(topicName)
+        on("$PREFIX.messages.sent.topic.count counter") {
+            val counterName = "$PREFIX.messages.sent.topic.count"
+            it("should handle counters for different topics") {
+                cut.notifyMessageSent(topicName1)
+                cut.notifyMessageSent(topicName2)
+                cut.notifyMessageSent(topicName2)
 
-                verifyCounter(registrySearch().name(counterName).tag("topic", topicName)) { counter ->
+                verifyCounter(registrySearch().name(counterName).tag("topic", topicName1)) { counter ->
                     assertThat(counter.count()).isCloseTo(1.0, doublePrecision)
                 }
-            }
-        }
 
-        it("should leave all other counters unchanged") {
-            cut.notifyMessageSent(topicName)
-            verifyAllCountersAreUnchangedBut(counterName)
+                verifyCounter(registrySearch().name(counterName).tag("topic", topicName2)) { counter ->
+                    assertThat(counter.count()).isCloseTo(2.0, doublePrecision)
+                }
+            }
         }
     }