Add monitoring support by means of micrometer.io

Closes ONAP-345

Change-Id: I58c145b1d37a6b32fbe5b157723c152eb571a2dd
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
Issue-ID: DCAEGEN2-601
diff --git a/hv-collector-main/pom.xml b/hv-collector-main/pom.xml
index a5a35ba..dbec1de 100644
--- a/hv-collector-main/pom.xml
+++ b/hv-collector-main/pom.xml
@@ -91,6 +91,14 @@
         </dependency>
 
         <dependency>
+            <groupId>io.arrow-kt</groupId>
+            <artifactId>arrow-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.arrow-kt</groupId>
+            <artifactId>arrow-syntax</artifactId>
+        </dependency>
+        <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
         </dependency>
@@ -109,6 +117,10 @@
             <classifier>${os.detected.classifier}</classifier>
         </dependency>
         <dependency>
+            <groupId>io.micrometer</groupId>
+            <artifactId>micrometer-registry-jmx</artifactId>
+        </dependency>
+        <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
         </dependency>
diff --git a/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt b/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt
new file mode 100644
index 0000000..8a8b6d3
--- /dev/null
+++ b/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetrics.kt
@@ -0,0 +1,67 @@
+/*
+ * ============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/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/main.kt b/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/main.kt
index b7d9702..1f2686b 100644
--- a/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/main.kt
+++ b/hv-collector-main/src/main/kotlin/org/onap/dcae/collectors/veshv/main/main.kt
@@ -39,7 +39,8 @@
 
         val collectorProvider = CollectorFactory(
                 resolveConfigurationProvider(serverConfiguration),
-                AdapterFactory.kafkaSink()
+                AdapterFactory.kafkaSink(),
+                MicrometerMetrics()
         ).createVesHvCollectorProvider()
         ServerFactory.createNettyTcpServer(serverConfiguration, collectorProvider).start().block()
     } catch (ex: WrongArgumentException) {
diff --git a/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt b/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt
new file mode 100644
index 0000000..675647c
--- /dev/null
+++ b/hv-collector-main/src/test/kotlin/org/onap/dcae/collectors/veshv/main/MicrometerMetricsTest.kt
@@ -0,0 +1,191 @@
+/*
+ * ============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.core.Try
+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 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
+
+/**
+ * @author Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
+ * @since June 2018
+ */
+object MicrometerMetricsTest : Spek({
+    val doublePrecision = Percentage.withPercentage(0.5)
+    lateinit var registry: SimpleMeterRegistry
+    lateinit var cut: MicrometerMetrics
+
+    beforeEachTest {
+        registry = SimpleMeterRegistry()
+        cut = MicrometerMetrics(registry)
+    }
+
+    fun registrySearch() = RequiredSearch.`in`(registry)
+
+    fun <M, T> verifyMeter(search: RequiredSearch, map: (RequiredSearch) -> M, verifier: (M) -> T) =
+            Try {
+                map(search)
+            }.fold(
+                    { ex -> assertThat(ex).doesNotThrowAnyException() },
+                    verifier
+            )
+
+    fun <T> verifyGauge(name: String, verifier: (Gauge) -> T) =
+            verifyMeter(registrySearch().name(name), RequiredSearch::gauge, verifier)
+
+    fun <T> verifyCounter(search: RequiredSearch, verifier: (Counter) -> T) =
+            verifyMeter(search, RequiredSearch::counter, verifier)
+
+    fun <T> verifyCounter(name: String, verifier: (Counter) -> T) =
+            verifyCounter(registrySearch().name(name), verifier)
+
+    fun verifyAllCountersAreUnchangedBut(vararg changedCounters: String) {
+        registry.meters
+                .filter { it is Counter }
+                .filterNot { it.id.name in changedCounters }
+                .forEach { assertThat((it as Counter).count()).isCloseTo(0.0, doublePrecision) }
+    }
+
+    describe("notifyBytesReceived") {
+
+        on("data.received.bytes counter") {
+            val counterName = "data.received.bytes"
+
+            it("should increment counter") {
+                val bytes = 128
+                cut.notifyBytesReceived(bytes)
+
+                verifyCounter(counterName) { counter ->
+                    assertThat(counter.count()).isCloseTo(bytes.toDouble(), doublePrecision)
+                }
+            }
+
+            it("should leave all other counters unchanged") {
+                cut.notifyBytesReceived(128)
+                verifyAllCountersAreUnchangedBut(counterName)
+            }
+        }
+    }
+
+    describe("notifyMessageReceived") {
+        on("messages.received.count counter") {
+            val counterName = "messages.received.count"
+
+            it("should increment counter") {
+                cut.notifyMessageReceived(777)
+
+                verifyCounter(counterName) { counter ->
+                    assertThat(counter.count()).isCloseTo(1.0, doublePrecision)
+                }
+            }
+        }
+
+        on("messages.received.bytes counter") {
+            val counterName = "messages.received.bytes"
+
+            it("should increment counter") {
+                val bytes = 888
+                cut.notifyMessageReceived(bytes)
+
+                verifyCounter(counterName) { counter ->
+                    assertThat(counter.count()).isCloseTo(bytes.toDouble(), doublePrecision)
+                }
+            }
+        }
+
+        it("should leave all other counters unchanged") {
+            cut.notifyMessageReceived(128)
+            verifyAllCountersAreUnchangedBut("messages.received.count", "messages.received.bytes")
+        }
+    }
+
+    describe("notifyMessageSent") {
+        val topicName = "dmaap_topic_name"
+        val counterName = "messages.sent.count"
+
+        on("$counterName counter") {
+
+            it("should increment counter") {
+                cut.notifyMessageSent(topicName)
+
+                verifyCounter(counterName) { counter ->
+                    assertThat(counter.count()).isCloseTo(1.0, doublePrecision)
+                }
+            }
+        }
+
+        on("$counterName[topic=$topicName] counter") {
+
+            it("should increment counter") {
+                cut.notifyMessageSent(topicName)
+
+                verifyCounter(registrySearch().name(counterName).tag("topic", topicName)) { counter ->
+                    assertThat(counter.count()).isCloseTo(1.0, doublePrecision)
+                }
+            }
+        }
+
+        it("should leave all other counters unchanged") {
+            cut.notifyMessageSent(topicName)
+            verifyAllCountersAreUnchangedBut(counterName)
+        }
+    }
+
+    describe("processing gauge") {
+        it("should show difference between sent and received messages") {
+
+            on("positive difference") {
+                cut.notifyMessageReceived(128)
+                cut.notifyMessageReceived(256)
+                cut.notifyMessageReceived(256)
+                cut.notifyMessageSent("hvranmeas")
+                verifyGauge("messages.processing.count") { gauge ->
+                    assertThat(gauge.value()).isCloseTo(2.0, doublePrecision)
+                }
+            }
+
+            on("zero difference") {
+                cut.notifyMessageReceived(128)
+                cut.notifyMessageSent("hvranmeas")
+                verifyGauge("messages.processing.count") { gauge ->
+                    assertThat(gauge.value()).isCloseTo(0.0, doublePrecision)
+                }
+            }
+
+            on("negative difference") {
+                cut.notifyMessageReceived(128)
+                cut.notifyMessageSent("calltrace")
+                cut.notifyMessageSent("hvranmeas")
+                verifyGauge("messages.processing.count") { gauge ->
+                    assertThat(gauge.value()).isCloseTo(0.0, doublePrecision)
+                }
+            }
+        }
+    }
+
+})