Update app.py

app.py

@@ -8,7 +8,8 @@ from fastapi import FastAPI
 from pydantic import BaseModel
 import uvicorn
 import openai 
-import socket # Added for explicit socket error handling
+import socket 
+import time # Added for retry mechanism
 
 # --- Configuration ---
 BASE_MODEL_ID = "meta-llama/Llama-3.1-8B-Instruct"
@@ -292,33 +293,52 @@ app = gr.mount_gradio_app(app, demo, path="/")
 if __name__ == "__main__":
     load_model()
     
-    # 1. Determine the primary port from the environment, defaulting to 7860
+    # 1. Determine the primary port and define a sequence of ports to try
     primary_port = int(os.environ.get("PORT", 7860))
+    # Create a list of ports to try, prioritizing the environment variable, then common Gradio ports
+    ports_to_try = [primary_port]
+    if 7860 not in ports_to_try:
+        ports_to_try.append(7860)
+    if 7861 not in ports_to_try:
+        ports_to_try.append(7861)
     
-    # Define the standard Gradio port as the fallback for robustness
-    fallback_port = 7860 if primary_port != 7860 else 7861
+    # Simple retry mechanism
+    max_retries = 3
+    server_started = False
     
-    # Attempt to run on the primary port
-    try:
-        print(f"Attempting to run Uvicorn on primary port {primary_port}")
-        uvicorn.run(app, host="0.0.0.0", port=primary_port, loop="asyncio")
-    
-    # Catch specific socket errors (Address already in use is often socket.error/OSError 98)
-    except (OSError, socket.error) as e:
-        # Check for "Address already in use" (Error code 98)
-        if getattr(e, 'errno', None) == 98 or "address already in use" in str(e).lower():
-            print(f"ERROR: Primary port {primary_port} is already in use. Trying fallback port {fallback_port}...")
-            
-            # Try running on the fallback port
+    for port in ports_to_try:
+        for attempt in range(max_retries):
             try:
-                uvicorn.run(app, host="0.0.0.0", port=fallback_port, loop="asyncio")
-            except (OSError, socket.error) as fallback_e:
-                # If the fallback fails, we must terminate.
-                if getattr(fallback_e, 'errno', None) == 98 or "address already in use" in str(fallback_e).lower():
-                    print(f"FATAL ERROR: Fallback port {fallback_port} also failed to bind. Process terminating.")
-                    raise fallback_e 
+                print(f"Attempting to run Uvicorn on port {port} (Attempt {attempt + 1}/{max_retries})")
+                uvicorn.run(app, host="0.0.0.0", port=port, loop="asyncio")
+                
+                # If uvicorn.run returns without an exception, the server has started (or shut down gracefully)
+                server_started = True 
+                print(f"Successfully started server on port {port}.")
+                # It's better to let uvicorn run indefinitely. If it exits here, it's usually due to a kill signal.
+                # However, in this environment, breaking and exiting is the standard procedure.
+                break 
+                
+            # Catch specific socket errors (Address already in use is often socket.error/OSError 98)
+            except (OSError, socket.error) as e:
+                # Check for "Address already in use" (Error code 98)
+                if getattr(e, 'errno', None) == 98 or "address already in use" in str(e).lower():
+                    print(f"WARNING: Port {port} is already in use. Retrying in 1 second...")
+                    time.sleep(1) # Wait a moment before retrying the same port
+                    
+                    if attempt == max_retries - 1:
+                        # If this was the last attempt for this port, move to the next port
+                        print(f"All {max_retries} attempts failed for port {port}. Trying next port in sequence.")
+                        break # Break inner loop to try next port in ports_to_try
                 else:
-                    raise fallback_e
-        else:
-            # Re-raise other unexpected errors
-            raise e
+                    # Re-raise other unexpected errors
+                    print(f"An unexpected error occurred: {e}")
+                    raise e
+        
+        if server_started:
+            # If the server started successfully, break the outer port loop
+            break 
+            
+    if not server_started:
+        print("FATAL ERROR: Failed to bind to any available port after multiple retries. Process terminating.")
+        exit(1) # Ensure process exits with failure code if no port is found.