Add an `isEphemeral` dimension to message delivery latency metrics

service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java

@@ -781,6 +781,10 @@ public class MessageController {
                     "rest",
                     auth.getAuthenticatedDevice().isPrimary(),
                     outgoingMessageEntity.urgent(),
+                    // Messages fetched via this endpoint (as opposed to WebSocketConnection) are never ephemeral
+                    // because, by definition, the client doesn't have a "live" connection via which to receive
+                    // ephemeral messages.
+                    false,
                     userAgent,
                     clientReleaseManager);
               })

service/src/main/java/org/whispersystems/textsecuregcm/metrics/MessageMetrics.java

@@ -72,14 +72,16 @@ public final class MessageMetrics {
       final String channel,
       final boolean isPrimaryDevice,
       final boolean isUrgent,
+      final boolean isEphemeral,
       final String userAgent,
       final ClientReleaseManager clientReleaseManager) {
 
-    final List<Tag> tags = new ArrayList<>(4);
+    final List<Tag> tags = new ArrayList<>();
     tags.add(UserAgentTagUtil.getPlatformTag(userAgent));
     tags.add(Tag.of("channel", channel));
     tags.add(Tag.of("isPrimary", String.valueOf(isPrimaryDevice)));
     tags.add(Tag.of("isUrgent", String.valueOf(isUrgent)));
+    tags.add(Tag.of("isEphemeral", String.valueOf(isEphemeral)));
 
     UserAgentTagUtil.getClientVersionTag(userAgent, clientReleaseManager).ifPresent(tags::add);
 

service/src/main/java/org/whispersystems/textsecuregcm/websocket/WebSocketConnection.java

@@ -255,6 +255,7 @@ public class WebSocketConnection implements WebSocketConnectionEventListener {
                 "websocket",
                 auth.getAuthenticatedDevice().isPrimary(),
                 message.getUrgent(),
+                message.getEphemeral(),
                 client.getUserAgent(),
                 clientReleaseManager);
           }