feat: prometheus metrics exporter

ingester-all/pom.xml

@@ -47,5 +47,9 @@
             <groupId>${project.groupId}</groupId>
             <artifactId>ingester-bulk-protocol</artifactId>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>ingester-prometheus-metrics</artifactId>
+        </dependency>
     </dependencies>
 </project>

ingester-example/src/main/java/io/greptime/BulkWriteApiQuickStart.java

@@ -118,6 +118,8 @@ public static void main(String[] args) throws Exception {
 
             bulkStreamWriter.completed();
         }
+
+        greptimeDB.shutdownGracefully();
     }
 
     private static Object[] generateOneRow(int cardinality) {

ingester-example/src/main/java/io/greptime/bench/BulkWriteBenchmark.java

@@ -19,8 +19,10 @@
 import io.greptime.BulkStreamWriter;
 import io.greptime.BulkWrite;
 import io.greptime.GreptimeDB;
+import io.greptime.common.util.MetricsUtil;
 import io.greptime.common.util.ServiceLoader;
 import io.greptime.common.util.SystemPropertyUtil;
+import io.greptime.metrics.MetricsExporter;
 import io.greptime.models.Table;
 import io.greptime.models.TableSchema;
 import io.greptime.rpc.Compression;
@@ -52,6 +54,10 @@ public static void main(String[] args) throws Exception {
         LOG.info("Using zstd compression: {}", zstdCompression);
         LOG.info("Batch size: {}", batchSize);
 
+        // Start a metrics exporter
+        MetricsExporter metricsExporter = new MetricsExporter(8080, MetricsUtil.metricRegistry());
+        metricsExporter.init(null);
+
         GreptimeDB greptimeDB = DBConnector.connectTo(new String[] {endpoint}, dbName);
 
         BulkWrite.Config cfg = BulkWrite.Config.newBuilder()
@@ -111,5 +117,6 @@ public static void main(String[] args) throws Exception {
         }
 
         greptimeDB.shutdownGracefully();
+        metricsExporter.shutdownGracefully();
     }
 }

ingester-example/src/main/java/io/greptime/bench/StreamingWriteBenchmark.java

@@ -18,8 +18,10 @@
 
 import io.greptime.GreptimeDB;
 import io.greptime.StreamWriter;
+import io.greptime.common.util.MetricsUtil;
 import io.greptime.common.util.ServiceLoader;
 import io.greptime.common.util.SystemPropertyUtil;
+import io.greptime.metrics.MetricsExporter;
 import io.greptime.models.Table;
 import io.greptime.models.TableSchema;
 import io.greptime.models.WriteOk;
@@ -55,6 +57,10 @@ public static void main(String[] args) throws Exception {
         LOG.info("Batch size: {}", batchSize);
         LOG.info("Max points per second: {}", maxPointsPerSecond);
 
+        // Start a metrics exporter
+        MetricsExporter metricsExporter = new MetricsExporter(8080, MetricsUtil.metricRegistry());
+        metricsExporter.init(null);
+
         GreptimeDB greptimeDB = DBConnector.connectTo(new String[] {endpoint}, dbName);
 
         Compression compression = zstdCompression ? Compression.Zstd : Compression.None;
@@ -100,5 +106,6 @@ public static void main(String[] args) throws Exception {
 
         greptimeDB.shutdownGracefully();
         tableDataProvider.close();
+        metricsExporter.shutdownGracefully();
     }
 }

ingester-prometheus-metrics/pom.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright 2023 Greptime Team
+
+    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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>io.greptime</groupId>
+        <artifactId>greptimedb-ingester</artifactId>
+        <version>0.14.2</version>
+    </parent>
+    <artifactId>ingester-prometheus-metrics</artifactId>
+
+    <properties>
+        <prometheus.version>0.16.0</prometheus.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.greptime</groupId>
+            <artifactId>ingester-common</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>simpleclient_dropwizard</artifactId>
+            <version>${prometheus.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>simpleclient_httpserver</artifactId>
+            <version>${prometheus.version}</version>
+        </dependency>
+    </dependencies>
+</project>

ingester-prometheus-metrics/src/main/java/io/greptime/metrics/MetricsExporter.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2023 Greptime Team
+ *
+ * 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.
+ */
+
+package io.greptime.metrics;
+
+import com.codahale.metrics.MetricRegistry;
+import io.greptime.common.Lifecycle;
+import io.prometheus.client.CollectorRegistry;
+import io.prometheus.client.dropwizard.DropwizardExports;
+import io.prometheus.client.exporter.HTTPServer;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MetricsExporter implements Lifecycle<Void> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(MetricsExporter.class);
+
+    private final CollectorRegistry prometheusMetricRegistry;
+
+    private final int port;
+    private HTTPServer server;
+
+    private final AtomicBoolean started = new AtomicBoolean(false);
+
+    public MetricsExporter(int port, MetricRegistry dropwizardMetricRegistry) {
+        this.port = port;
+        this.prometheusMetricRegistry = new CollectorRegistry();
+        this.prometheusMetricRegistry.register(new DropwizardExports(dropwizardMetricRegistry));
+    }
+
+    @Override
+    public boolean init(Void opts) {
+        if (this.started.compareAndSet(false, true)) {
+            try {
+                this.server = new HTTPServer(new InetSocketAddress(this.port), this.prometheusMetricRegistry);
+                LOG.info("Metrics exporter started at `http://localhost:{}/metrics`", this.port);
+                return true;
+            } catch (IOException e) {
+                this.started.set(false);
+                LOG.error("Failed to start metrics exporter", e);
+                throw new RuntimeException("Failed to start metrics exporter", e);
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public void shutdownGracefully() {
+        if (this.started.compareAndSet(true, false)) {
+            if (this.server != null) {
+                this.server.close();
+                LOG.info("Metrics exporter stopped");
+            }
+        }
+    }
+}

pom.xml

@@ -52,6 +52,7 @@
         <module>ingester-example</module>
         <module>ingester-all</module>
         <module>ingester-bulk-protocol</module>
+        <module>ingester-prometheus-metrics</module>
     </modules>
 
     <scm>
@@ -122,6 +123,11 @@
                 <artifactId>ingester-grpc</artifactId>
                 <version>${project.version}</version>
             </dependency>
+            <dependency>
+                <groupId>${project.groupId}</groupId>
+                <artifactId>ingester-prometheus-metrics</artifactId>
+                <version>${project.version}</version>
+            </dependency>
             <dependency>
                 <groupId>${project.groupId}</groupId>
                 <artifactId>ingester-protocol</artifactId>