Add support for OpenTelemetry (#995)

* Added support for OpenTelemetry

Signed-off-by: dhoard <[email protected]>

Author: dhoard

.gitignore

@@ -10,12 +10,7 @@ target/
 .settings/
 .classpath
 dependency-reduced-pom.xml
-output.txt
 pom.xml.versionsBackup
 integration_test_suite/integration_tests/src/test/resources/common/**.jar
-output.log
-stress-test.log
-test.sh
-test.log
-verify-full.sh
-verify-full.log
+smoke-test.log
+regression-test.log

MAINTAINER_NOTES.md

@@ -57,19 +57,19 @@ Example
 
 ```shell
 /home/dhoard/Downloads/jmx_prometheus_javaagent-0.20.0.jar
-/home/dhoard/Downloads/jmx_prometheus_httpserver-0.20.0.jar
+/home/dhoard/Downloads/jmx_prometheus_standalone-0.20.0.jar
 ```
 
 Command
 
 ```shell
-./tools/patch-and-run-integration-test-suite.sh <javaagent.jar> <httpserver.jar>
+./tools/patch-and-run-integration-test-suite.sh <javaagent.jar> <standalone.jar>
 ```
 
 Example
 
 ```shell
-./tools/patch-and-run-integration-test-suite.sh /home/dhoard/Downloads/jmx_prometheus_javaagent-0.20.0.jar /home/dhoard/Downloads/jmx_prometheus_httpserver-0.20.0.jar
+./tools/patch-and-run-integration-test-suite.sh /home/dhoard/Downloads/jmx_prometheus_javaagent-0.20.0.jar /home/dhoard/Downloads/jmx_prometheus_standalone-0.20.0.jar
 ```
 
 ### Step 3

collector/pom.xml

@@ -40,6 +40,27 @@
                     <compilerArgument>-Xbootclasspath/a:${env.JAVA_HOME}/lib/</compilerArgument>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>com.diffplug.spotless</groupId>
+                <artifactId>spotless-maven-plugin</artifactId>
+                <configuration>
+                    <java>
+                        <googleJavaFormat>
+                            <version>1.24.0</version>
+                            <style>AOSP</style>
+                            <reflowLongStrings>true</reflowLongStrings>
+                        </googleJavaFormat>
+                    </java>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>apply</goal>
+                        </goals>
+                        <phase>compile</phase>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>3.5.2</version>

collector/src/main/java/io/prometheus/jmx/BuildInfoMetrics.java

@@ -31,7 +31,13 @@
  * Metrics being exported:
  *
  * <pre>
- *   jmx_exporter_build_info{version="3.2.0",name="jmx_prometheus_httpserver",} 1.0
+ *   jmx_exporter_build_info{version="3.2.0",name="jmx_prometheus_javaagent",} 1.0
+ * </pre>
+ *
+ * or
+ *
+ * <pre>
+ *   jmx_exporter_build_info{version="3.2.0",name="jmx_prometheus_standalone",} 1.0
  * </pre>
  */
 public class BuildInfoMetrics {

collector/src/main/java/io/prometheus/jmx/JmxCollector.java

@@ -181,7 +181,7 @@ private void exitOnConfigError() {
             LOGGER.log(
                     SEVERE,
                     "Configuration error: When running jmx_exporter in standalone mode (using"
-                            + " jmx_prometheus_httpserver-*.jar) you must configure 'jmxUrl' or"
+                            + " jmx_prometheus_standalone-*.jar) you must configure 'jmxUrl' or"
                             + " 'hostPort'.");
             System.exit(-1);
         }

collector/src/main/java/io/prometheus/jmx/JmxScraper.java

@@ -22,8 +22,23 @@
 import io.prometheus.jmx.logger.LoggerFactory;
 import java.io.IOException;
 import java.lang.management.ManagementFactory;
-import java.util.*;
-import javax.management.*;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.TreeSet;
+import javax.management.Attribute;
+import javax.management.AttributeList;
+import javax.management.JMException;
+import javax.management.MBeanAttributeInfo;
+import javax.management.MBeanInfo;
+import javax.management.MBeanServerConnection;
+import javax.management.ObjectInstance;
+import javax.management.ObjectName;
 import javax.management.openmbean.CompositeData;
 import javax.management.openmbean.CompositeType;
 import javax.management.openmbean.TabularData;

collector/src/main/java/io/prometheus/jmx/MatchedRuleToMetricSnapshotsConverter.java

@@ -18,8 +18,18 @@
 
 import io.prometheus.jmx.logger.Logger;
 import io.prometheus.jmx.logger.LoggerFactory;
-import io.prometheus.metrics.model.snapshots.*;
-import java.util.*;
+import io.prometheus.metrics.model.snapshots.CounterSnapshot;
+import io.prometheus.metrics.model.snapshots.GaugeSnapshot;
+import io.prometheus.metrics.model.snapshots.Labels;
+import io.prometheus.metrics.model.snapshots.MetricSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricSnapshots;
+import io.prometheus.metrics.model.snapshots.UnknownSnapshot;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.logging.Level;
 
 public class MatchedRuleToMetricSnapshotsConverter {

collector/src/main/java/io/prometheus/jmx/logger/Logger.java

@@ -16,6 +16,8 @@
 
 package io.prometheus.jmx.logger;
 
+import static java.lang.String.format;
+
 import java.util.logging.Level;
 
 /** Class to implement a Logger */
@@ -55,13 +57,11 @@ public boolean isLoggable(Level level) {
      */
     public void log(Level level, String message, Object... objects) {
         if (LOGGER.isLoggable(level)) {
-            LOGGER.log(level, String.format(message, objects));
+            LOGGER.log(level, format(message, objects));
         }
 
         if (JMX_PROMETHEUS_EXPORTER_DEVELOPER_DEBUG) {
-            System.out
-                    .format("[%s] %s %s", level, LOGGER.getName(), String.format(message, objects))
-                    .println();
+            System.out.printf("[%s] %s %s%n", level, LOGGER.getName(), format(message, objects));
         }
     }
 }

collector/src/test/java/io/prometheus/jmx/ObjectNameAttributeFilterTest.java

@@ -16,10 +16,17 @@
 
 package io.prometheus.jmx;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import java.lang.reflect.Field;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
 import javax.management.MalformedObjectNameException;
 import javax.management.ObjectName;
 import org.junit.Test;

docs/README.md

@@ -5,17 +5,22 @@
 JMX Exporter
 =====
 
-JMX to Prometheus exporter: a collector that can configurable scrape and
-expose mBeans of a JMX target.
+JMX to Prometheus exporter:
 
-This exporter is intended to be run as a Java Agent, exposing a HTTP server
-and serving metrics of the local JVM. It can be also run as a standalone
-HTTP server and scrape remote JMX targets, but this has various
+A collector that can configurable scrape and expose MBeans of a JMX target.
+
+This exporter is intended to be run as a Java Agent, exposing either
+an HTTP endpoint or pushing Open Telemetry metrics of the local JVM.
+
+It can be also run as a standalone server and scrape remote JMX targets, but this has various
 disadvantages, such as being harder to configure and being unable to expose
-process metrics (e.g., memory and CPU usage). In particular all the
-`jvm_*` metrics like `jvm_classes_loaded_total`, `jvm_threads_current`,
-`jvm_threads_daemon` and `jvm_memory_bytes_used` won't be availabe if
-using the standalone http server.
+process metrics (e.g., memory and CPU usage).
+
+In particular all the `jvm_*` metrics like `jvm_classes_loaded_total`, `jvm_threads_current`,
+`jvm_threads_daemon` and `jvm_memory_bytes_used` won't be available when
+using the standalone server.
+
+**Running the exporter as a Java agent is strongly encouraged.**
 
 ### **NOTES**
 
@@ -52,21 +57,21 @@ rules:
 
 Example configurations can be found in the `example_configs/` directory.
 
-## Running the Standalone HTTP Server
+## Running the Standalone Server
 
-- [jmx_prometheus_httpserver-1.0.1.jar](https://repo1.maven.org/maven2/io/prometheus/jmx/jmx_prometheus_httpserver/1.0.1/jmx_prometheus_httpserver-1.0.1.jar)
+- [jmx_prometheus_standalone-1.0.1.jar](https://repo1.maven.org/maven2/io/prometheus/jmx/jmx_prometheus_standalone/1.0.1/jmx_prometheus_standalone-1.0.1.jar)
 
-To run the standalone HTTP server, download one of the JARs and run:
+To run the standalone server, download one of the JARs and run:
 
 ```
-java -jar jmx_prometheus_httpserver-1.0.1.jar 12345 config.yaml
+java -jar jmx_prometheus_standalone-1.0.1.jar 12345 config.yaml
 ```
 
 Metrics will now be accessible at [http://localhost:12345/metrics](http://localhost:12345/metrics).
 To bind the java agent to a specific IP change the port number to `host:port`.
 
-The standalone HTTP server will read JMX remotely over the network. Therefore, you need to specify
-either `hostPort` or `jmxUrl` in `config.yaml` to tell the HTTP server where the JMX beans can be accessed.
+The standalone server will read JMX remotely over the network. Therefore, you need to specify
+either `hostPort` or `jmxUrl` in `config.yaml` to tell the server where the JMX beans can be accessed.
 
 A minimal `config.yaml` looks like this:
 
@@ -76,7 +81,7 @@ rules:
 - pattern: ".*"
 ```
 
-As stated above, it is recommended to run JMX exporter as a Java agent and not as a standalone HTTP server.
+As stated above, it is recommended to run JMX exporter as a Java agent and not as a standalone server.
 
 **NOTES**