From ebecb1caec82d9256d2c3ef26a3647f4709184b4 Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon@signal.org>
Date: Fri, 28 Jun 2024 17:14:42 -0400
Subject: [PATCH] Throw an exception if metric registries are configured more
 than once

---
 .../textsecuregcm/metrics/MetricsUtil.java          | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MetricsUtil.java b/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MetricsUtil.java
index 00f38f2e9..4509f40ef 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MetricsUtil.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MetricsUtil.java
@@ -19,6 +19,8 @@ import io.micrometer.core.instrument.binder.system.ProcessorMetrics;
 import io.micrometer.core.instrument.config.MeterFilter;
 import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
 import io.micrometer.statsd.StatsdMeterRegistry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.WhisperServerConfiguration;
 import org.whispersystems.textsecuregcm.WhisperServerVersion;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
@@ -30,6 +32,10 @@ public class MetricsUtil {
 
   public static final String PREFIX = "chat";
 
+  private static volatile boolean registeredMetrics = false;
+
+  private static final Logger log = LoggerFactory.getLogger(MetricsUtil.class);
+
   /**
    * Returns a dot-separated ('.') name for the given class and name parts
    */
@@ -48,6 +54,13 @@ public class MetricsUtil {
 
   public static void configureRegistries(final WhisperServerConfiguration config, final Environment environment,
       DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager) {
+
+    if (registeredMetrics) {
+      throw new IllegalStateException("Metric registries configured more than once");
+    }
+
+    registeredMetrics = true;
+
     SharedMetricRegistries.add(Constants.METRICS_NAME, environment.metrics());
 
     {