Add Experiment#compareMonoResult

service/src/main/java/org/whispersystems/textsecuregcm/experiment/Experiment.java

@@ -18,6 +18,7 @@ import java.util.concurrent.Executor;
 import java.util.function.Supplier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
 
 /**
  * An experiment compares the results of two operations and records metrics to assess how frequently they match.
@@ -70,6 +71,14 @@ public class Experiment {
     this.experimentNullMismatchTimer = experimentNullMismatchTimer;
   }
 
+  public <T> void compareMonoResult(final T expected, final Mono<T> experimentMono) {
+    final Timer.Sample sample = Timer.start();
+
+    experimentMono.subscribe(
+        actual -> recordResult(expected, actual, sample),
+        cause -> recordError(cause, sample));
+  }
+
   public <T> void compareFutureResult(final T expected, final CompletionStage<T> experimentStage) {
     final Timer.Sample sample = Timer.start();
 

service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagesCache.java

@@ -463,8 +463,7 @@ public class MessagesCache extends RedisClusterPubSubAdapter<String, String> imp
             }
           });
 
-      experiment.compareFutureResult(mrmMessage.toBuilder().clearSharedMrmKey().build(),
+      experiment.compareMonoResult(mrmMessage.toBuilder().clearSharedMrmKey().build(), mrmMessageMono);
-          mrmMessageMono.toFuture());
 
       return mrmMessageMono;
     } else {