fix: Improve graceful shutdown

server/collaboration/tracing.js

@@ -2,7 +2,7 @@
 import Metrics from "../logging/metrics";
 
 export default class Tracing {
-  async onCreateDocument({
+  onCreateDocument({
     documentName,
     instance,
   }: {
@@ -17,11 +17,11 @@ export default class Tracing {
     );
   }
 
-  async onAuthenticationFailed({ documentName }: { documentName: string }) {
+  onAuthenticationFailed({ documentName }: { documentName: string }) {
     Metrics.increment("collaboration.authentication_failed", { documentName });
   }
 
-  async onConnect({
+  onConnect({
     documentName,
     instance,
   }: {
@@ -35,7 +35,7 @@ export default class Tracing {
     );
   }
 
-  async onDisconnect({
+  onDisconnect({
     documentName,
     instance,
   }: {
@@ -54,7 +54,12 @@ export default class Tracing {
     );
   }
 
-  async onChange({ documentName }: { documentName: string }) {
+  onChange({ documentName }: { documentName: string }) {
     Metrics.increment("collaboration.change", { documentName });
   }
+
+  onDestroy() {
+    Metrics.gaugePerInstance("collaboration.connections_count", 0);
+    Metrics.gaugePerInstance("collaboration.documents_count", 0);
+  }
 }