diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/sqs/DirectoryQueue.java b/service/src/main/java/org/whispersystems/textsecuregcm/sqs/DirectoryQueue.java
index 36684f893..c385720af 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/sqs/DirectoryQueue.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/sqs/DirectoryQueue.java
@@ -11,13 +11,12 @@ import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.SharedMetricRegistries;
 import com.codahale.metrics.Timer;
 import com.google.common.annotations.VisibleForTesting;
-import java.util.Collections;
-import java.util.IdentityHashMap;
+import io.dropwizard.lifecycle.Managed;
+import io.micrometer.core.instrument.Metrics;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.UUID;
-import io.dropwizard.lifecycle.Managed;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.configuration.SqsConfiguration;
@@ -44,7 +43,7 @@ public class DirectoryQueue implements Managed {
   private final List<String> queueUrls;
   private final SqsAsyncClient sqs;
 
-  private final Set<SendMessageRequest> outstandingRequests = Collections.newSetFromMap(new IdentityHashMap<>());
+  private final AtomicInteger outstandingRequests = new AtomicInteger();
 
   private enum UpdateAction {
     ADD("add"),
@@ -71,6 +70,8 @@ public class DirectoryQueue implements Managed {
         .region(Region.of(sqsConfig.getRegion()))
         .credentialsProvider(credentialsProvider)
         .build();
+
+    Metrics.gauge(name(getClass(), "outstandingRequests"), outstandingRequests);
   }
 
   @VisibleForTesting
@@ -86,7 +87,7 @@ public class DirectoryQueue implements Managed {
   @Override
   public void stop() throws Exception {
     synchronized (outstandingRequests) {
-      while (!outstandingRequests.isEmpty()) {
+      while (outstandingRequests.get() > 0) {
         outstandingRequests.wait();
       }
     }
@@ -123,7 +124,7 @@ public class DirectoryQueue implements Managed {
           .build();
 
       synchronized (outstandingRequests) {
-        outstandingRequests.add(request);
+        outstandingRequests.incrementAndGet();
       }
 
       sqs.sendMessage(request).whenComplete((response, cause) -> {
@@ -139,7 +140,7 @@ public class DirectoryQueue implements Managed {
           }
         } finally {
           synchronized (outstandingRequests) {
-            outstandingRequests.remove(request);
+            outstandingRequests.decrementAndGet();
             outstandingRequests.notifyAll();
           }