[web] restrict external heartbeat/server ping to websocket transport (#23830)

Co-authored-by: Alf Eaton <alf.eaton@overleaf.com>
GitOrigin-RevId: c03a78e2c05cd380b705bd14652060980682cb39

services/real-time/app/js/Router.js

@@ -175,7 +175,10 @@ module.exports = Router = {
         return
       }
       const useServerPing =
-        !!client.handshake?.query?.esh && !!client.handshake?.query?.ssp
+        !!client.handshake?.query?.esh &&
+        !!client.handshake?.query?.ssp &&
+        // No server ping with long-polling transports.
+        client.transport === 'websocket'
       const isDebugging = !!client.handshake?.query?.debugging
       const projectId = client.handshake?.query?.projectId
 

services/web/frontend/js/features/ide-react/connection/connection-manager.ts

@@ -248,10 +248,13 @@ export class ConnectionManager extends EventTarget {
       if (this.externalHeartbeatInterval) {
         window.clearInterval(this.externalHeartbeatInterval)
       }
-      this.externalHeartbeatInterval = window.setInterval(
-        () => this.sendExternalHeartbeat(),
-        15_000
-      )
+      if (this.socket.socket.transport?.name === 'websocket') {
+        // Do not enable external heartbeat on polling transports.
+        this.externalHeartbeatInterval = window.setInterval(
+          () => this.sendExternalHeartbeat(),
+          15_000
+        )
+      }
     }
     // Reset on success regardless of transport. We want to upgrade back to websocket on reconnect.
     this.websocketFailureCount = 0