add configuration for heartbeat and proper te\sts for reconnect

Author: T4rk1n

.ai/ARCHITECTURE.md

@@ -905,12 +905,14 @@ app = Dash(
     server=server,
     websocket_callbacks=True,
     websocket_inactivity_timeout=300000,  # 5 minutes (default)
+    websocket_heartbeat_interval=30000,   # 30 seconds (default)
     websocket_allowed_origins=['https://example.com'],
 )
 ```
 
 - **`websocket_callbacks`** - Enable WebSocket for all callbacks (default: `False`)
 - **`websocket_inactivity_timeout`** - Close WebSocket after period of inactivity in milliseconds (default: `300000` = 5 minutes). Heartbeats do not count as activity. Set to `0` to disable timeout. Connection automatically reconnects when needed.
+- **`websocket_heartbeat_interval`** - Interval for heartbeat/keep-alive checks in milliseconds (default: `30000` = 30 seconds). Also determines how frequently inactivity timeout is checked.
 - **`websocket_allowed_origins`** - List of allowed origins for WebSocket connections (security)
 
 ### Architecture

@plotly/dash-websocket-worker/src/types.ts

@@ -40,6 +40,7 @@ export interface ConnectMessage extends WorkerMessage {
     payload: {
         serverUrl: string;
         inactivityTimeout?: number;
+        heartbeatInterval?: number;
     };
 }
 

@plotly/dash-websocket-worker/src/worker.ts

@@ -81,16 +81,24 @@ self.onconnect = (event: MessageEvent) => {
                 const rendererId = connectMsg.rendererId;
                 const newServerUrl = connectMsg.payload.serverUrl;
                 const inactivityTimeout = connectMsg.payload.inactivityTimeout;
+                const heartbeatInterval = connectMsg.payload.heartbeatInterval;
 
                 // Register the renderer
                 router.registerRenderer(rendererId, port);
                 rendererIds.add(rendererId);
 
-                console.log(`[DashWSWorker] Renderer ${rendererId} connected, inactivityTimeout: ${inactivityTimeout}`);
+                console.log(`[DashWSWorker] Renderer ${rendererId} connected, inactivityTimeout: ${inactivityTimeout}, heartbeatInterval: ${heartbeatInterval}`);
 
-                // Update inactivity timeout if provided
+                // Update config if provided
+                const configUpdate: {inactivityTimeout?: number; heartbeatInterval?: number} = {};
                 if (typeof inactivityTimeout === 'number') {
-                    wsManager.setConfig({ inactivityTimeout });
+                    configUpdate.inactivityTimeout = inactivityTimeout;
+                }
+                if (typeof heartbeatInterval === 'number') {
+                    configUpdate.heartbeatInterval = heartbeatInterval;
+                }
+                if (Object.keys(configUpdate).length > 0) {
+                    wsManager.setConfig(configUpdate);
                 }
 
                 // Connect to server if not already connected

dash/dash-renderer/src/config.ts

@@ -27,6 +27,7 @@ export type DashConfig = {
         url: string;
         worker_url: string;
         inactivity_timeout?: number;
+        heartbeat_interval?: number;
     };
     csrf_token_name?: string;
     csrf_header_name?: string;

dash/dash-renderer/src/utils/workerClient.ts

@@ -87,11 +87,13 @@ class WorkerClient {
      * @param workerUrl URL to the SharedWorker script
      * @param serverUrl WebSocket server URL
      * @param inactivityTimeout Optional inactivity timeout in ms
+     * @param heartbeatInterval Optional heartbeat interval in ms
      */
     public async connect(
         workerUrl: string,
         serverUrl: string,
-        inactivityTimeout?: number
+        inactivityTimeout?: number,
+        heartbeatInterval?: number
     ): Promise<void> {
         if (this.worker) {
             // Already connected
@@ -120,7 +122,8 @@ class WorkerClient {
             rendererId: this.rendererId,
             payload: {
                 serverUrl,
-                inactivityTimeout
+                inactivityTimeout,
+                heartbeatInterval
             }
         });
 
@@ -160,6 +163,7 @@ class WorkerClient {
             url?: string;
             worker_url?: string;
             inactivity_timeout?: number;
+            heartbeat_interval?: number;
         };
     }): Promise<void> {
         // Already connected
@@ -191,7 +195,8 @@ class WorkerClient {
         await this.connect(
             config.websocket.worker_url,
             wsUrl,
-            config.websocket.inactivity_timeout
+            config.websocket.inactivity_timeout,
+            config.websocket.heartbeat_interval
         );
     }
 

dash/dash.py

@@ -488,6 +488,7 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
         websocket_callbacks: Optional[bool] = False,
         websocket_allowed_origins: Optional[List[str]] = None,
         websocket_inactivity_timeout: Optional[int] = 300000,
+        websocket_heartbeat_interval: Optional[int] = 30000,
         websocket_batch_delay: Optional[float] = 0.005,
         **obsolete,
     ):
@@ -648,6 +649,7 @@ def __init__(  # pylint: disable=too-many-statements, too-many-branches
         self._websocket_callbacks = websocket_callbacks
         self._websocket_allowed_origins = websocket_allowed_origins or []
         self._websocket_inactivity_timeout = websocket_inactivity_timeout
+        self._websocket_heartbeat_interval = websocket_heartbeat_interval
         self._websocket_batch_delay = websocket_batch_delay
 
         self.logger = logging.getLogger(__name__)
@@ -998,6 +1000,7 @@ def _config(self):
                 "url": self.config.requests_pathname_prefix + "_dash-ws-callback",
                 "worker_url": self._get_worker_url(),
                 "inactivity_timeout": self._websocket_inactivity_timeout,
+                "heartbeat_interval": self._websocket_heartbeat_interval,
             }
 
         return config

tests/websocket/test_ws_inactivity.py

@@ -19,6 +19,7 @@ def test_ws020_inactivity_timeout_closes(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=3000,  # 3 seconds for testing
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(
@@ -54,6 +55,7 @@ def test_ws021_activity_resets_timer(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=4000,  # 4 seconds
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(
@@ -88,6 +90,7 @@ def test_ws022_quick_successive_callbacks(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=5000,
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(
@@ -121,6 +124,7 @@ def test_ws023_auto_reconnect_after_timeout(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=2000,  # 2 seconds
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(
@@ -164,6 +168,7 @@ def test_ws024_long_callback_doesnt_timeout(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=3000,  # 3 seconds
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(

tests/websocket/test_ws_reconnect.py

@@ -118,6 +118,7 @@ def test_ws033_callback_after_reconnect(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=2000,  # 2 seconds
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(
@@ -211,6 +212,7 @@ def test_ws035_long_callback_with_shutdown_check(dash_duo):
         backend="fastapi",
         websocket_callbacks=True,
         websocket_inactivity_timeout=2000,  # 2 seconds
+        websocket_heartbeat_interval=1000,  # 1 second - check inactivity frequently
     )
 
     app.layout = html.Div(