From 810e225915972d214488e90007c11ee8c242707a Mon Sep 17 00:00:00 2001
From: ruscalworld <me@ruscal.world>
Date: Tue, 20 Jun 2023 16:56:40 +0300
Subject: [PATCH] Add Hotspot metrics

---
 build.gradle                                          |  1 +
 .../ru/ruscalworld/fabricexporter/FabricExporter.java |  5 +++++
 .../ruscalworld/fabricexporter/config/MainConfig.java | 11 +++++++++++
 src/main/resources/config/exporter.properties         |  9 +++++++--
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/build.gradle b/build.gradle
index 7007665..9a9b3c5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -36,6 +36,7 @@ dependencies {
     // You may need to force-disable transitiveness on them.
     implementation "io.prometheus:simpleclient:${project.prometheus_version}"
     implementation "io.prometheus:simpleclient_httpserver:${project.prometheus_version}"
+    implementation "io.prometheus:simpleclient_hotspot:${project.prometheus_version}"
 
     compileOnly "me.lucko:spark-api:0.1-SNAPSHOT"
 }
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java b/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java
index 26c63e2..c2236c5 100644
--- a/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java
+++ b/src/main/java/ru/ruscalworld/fabricexporter/FabricExporter.java
@@ -1,6 +1,7 @@
 package ru.ruscalworld.fabricexporter;
 
 import io.prometheus.client.exporter.HTTPServer;
+import io.prometheus.client.hotspot.DefaultExports;
 import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
 import net.fabricmc.loader.api.FabricLoader;
@@ -44,6 +45,10 @@ public class FabricExporter implements ModInitializer {
         metricRegistry.registerDefault();
         this.setMetricRegistry(metricRegistry);
 
+        if (config.shouldExportJvmDefaults()) {
+            DefaultExports.initialize();
+        }
+
         ServerLifecycleEvents.SERVER_STARTING.register(this::setServer);
         ServerLifecycleEvents.SERVER_STARTED.register(server -> {
             try {
diff --git a/src/main/java/ru/ruscalworld/fabricexporter/config/MainConfig.java b/src/main/java/ru/ruscalworld/fabricexporter/config/MainConfig.java
index 7f215cb..34e352d 100644
--- a/src/main/java/ru/ruscalworld/fabricexporter/config/MainConfig.java
+++ b/src/main/java/ru/ruscalworld/fabricexporter/config/MainConfig.java
@@ -8,6 +8,7 @@ public class MainConfig extends Config {
     private int port;
     private int updateInterval;
     private boolean useSpark;
+    private boolean exportJvmDefaults;
 
     public MainConfig(String name) {
         super(name);
@@ -24,6 +25,8 @@ public class MainConfig extends Config {
         this.setUpdateInterval(ConvertUtil.intToStringOrDefault(updateIntervalString, 1000));
 
         this.setShouldUseSpark(properties.getProperty("use-spark", "true").equalsIgnoreCase("true"));
+
+        this.setShouldExportJvmDefaults(properties.getProperty("export-default-jvm-metrics", "true").equalsIgnoreCase("true"));
     }
 
     public int getPort() {
@@ -49,4 +52,12 @@ public class MainConfig extends Config {
     public void setShouldUseSpark(boolean useSpark) {
         this.useSpark = useSpark;
     }
+
+    public boolean shouldExportJvmDefaults() {
+        return exportJvmDefaults;
+    }
+
+    public void setShouldExportJvmDefaults(boolean exportJvmDefaults) {
+        this.exportJvmDefaults = exportJvmDefaults;
+    }
 }
diff --git a/src/main/resources/config/exporter.properties b/src/main/resources/config/exporter.properties
index bed1a7c..ab65ba4 100644
--- a/src/main/resources/config/exporter.properties
+++ b/src/main/resources/config/exporter.properties
@@ -1,4 +1,4 @@
-# On which port webserver should be started?
+# On which port Prometheus webserver should be started?
 # Default: 25585
 server-port=25585
 
@@ -14,6 +14,11 @@ update-interval=1000
 # Default: true
 use-spark=true
 
+# Should FabricExporter register default Hotspot exports?
+# This enables advanced metrics for JVM
+# Default: true
+export-default-jvm-metrics=true
+
 # You can disable any metric that registered via MetricRegistry (all metrics by default) using the settings below
 # Names of properties consist of "enable" and metric name without prefix and "_" replaced with "-"
 # For example, if you want to disable "minecraft_players_online", you should set "enable-players-online" to "false"
@@ -46,4 +51,4 @@ enable-entities=true
 
 # Exports count of handshake requests
 # Collected by FabricExporter
-enable-handshakes=true
\ No newline at end of file
+enable-handshakes=true