Make cluster master weight auto-adjustment conditional on explicit setting

- Added weight_explicit flag to track if --weight was specified on command line
- Automatic weight changes (100->0 on first client, 0->100 on last disconnect) only apply when weight is not explicitly set
- When --weight is specified, master maintains the explicit weight regardless of client connections
- Updated command line help and startup messages to clarify the behavior
- This allows administrators to override automatic weight management when needed

vidai/cluster_master.py

@@ -29,6 +29,7 @@ import websockets
 import ssl
 import os
 import ipaddress
+import sys
 from typing import Dict, Any, List, Optional
 from collections import defaultdict
 
@@ -36,10 +37,11 @@ from collections import defaultdict
 class ClusterMaster:
     """Master server for cluster coordination."""
 
-    def __init__(self, port: int = 5003, shared_dir: str = None, weight: int = 0):
+    def __init__(self, port: int = 5003, shared_dir: str = None, weight: int = 100, weight_explicit: bool = False):
         self.port = port
         self.shared_dir = shared_dir
-        self.weight = weight  # Master weight (default 0)
+        self.weight = weight  # Master weight (default 100, changes to 0 when clients connect if not explicit)
+        self.weight_explicit = weight_explicit  # Whether weight was explicitly set via command line
         self.server_sock: Optional[socket.socket] = None
         self.clients = {}  # type: Dict[str, Dict[str, Any]]
         self.client_websockets = {}  # type: Dict[str, websockets.WebSocketServerProtocol]
@@ -207,6 +209,11 @@ class ClusterMaster:
         self.client_websockets[client_id] = websocket
         self.tokens[token] = client_id
 
+        # If this is the first client and weight wasn't explicitly set, change master weight to 0
+        if len(self.clients) == 1 and self.weight == 100 and not self.weight_explicit:
+            self.weight = 0
+            print("First client connected - changing master weight to 0 (automatic)")
+
         print(f"Client {client_id} authenticated")
         return {'type': 'auth_success', 'client_id': client_id}
 
@@ -266,6 +273,11 @@ class ClusterMaster:
             for proc_type, queue in self.process_queue.items():
                 self.process_queue[proc_type] = [(k, w) for k, w in queue if k != proc_key]
 
+        # If no clients remain and weight wasn't explicitly set, change master weight back to 100
+        if len(self.clients) == 0 and self.weight == 0 and not self.weight_explicit:
+            self.weight = 100
+            print("All clients disconnected - changing master weight back to 100 (automatic)")
+
         print(f"Client {client_id} disconnected")
 
     def get_best_worker(self, process_type: str, prefer_local: bool = False) -> Optional[str]:
@@ -609,11 +621,12 @@ class ClusterMaster:
 cluster_master = ClusterMaster()
 
 
-def start_cluster_master(port: int = 5003, shared_dir: str = None, weight: int = 0) -> None:
+def start_cluster_master(port: int = 5003, shared_dir: str = None, weight: int = 100, weight_explicit: bool = False) -> None:
     """Start the cluster master server."""
     cluster_master.port = port
     cluster_master.shared_dir = shared_dir
     cluster_master.weight = weight
+    cluster_master.weight_explicit = weight_explicit
     asyncio.run(cluster_master.start())
 
 
@@ -623,11 +636,18 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser(description='VidAI Cluster Master')
     parser.add_argument('--port', type=int, default=5003, help='Port to listen on (default: 5003)')
     parser.add_argument('--shared-dir', help='Shared directory for file transfers')
-    parser.add_argument('--weight', type=int, default=0, help='Master weight for load balancing (default: 0)')
+    parser.add_argument('--weight', type=int, default=100, help='Master weight for load balancing (default: 100, auto-adjusts when clients connect unless explicitly set)')
 
     args = parser.parse_args()
 
-    print(f"Starting VidAI Cluster Master on port {args.port} with weight {args.weight}")
+    # Check if weight was explicitly provided
+    weight_explicit = '--weight' in sys.argv
+
+    if weight_explicit:
+        print(f"Starting VidAI Cluster Master on port {args.port} with explicit weight {args.weight}")
+    else:
+        print(f"Starting VidAI Cluster Master on port {args.port} with default weight {args.weight} (will auto-adjust when clients connect)")
+
     if args.shared_dir:
         print(f"Using shared directory: {args.shared_dir}")
         # Validate shared directory exists
@@ -635,4 +655,4 @@ if __name__ == "__main__":
             print(f"Warning: Shared directory {args.shared_dir} does not exist. Creating it.")
             os.makedirs(args.shared_dir, exist_ok=True)
 
-    start_cluster_master(args.port, args.shared_dir, args.weight)
+    start_cluster_master(args.port, args.shared_dir, args.weight, weight_explicit)
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