added queue

app.py

@@ -379,11 +379,13 @@ with gr.Blocks(
             metrics_output,
             generation_counter,
         ],
+        concurrency_limit=2,
+        concurrency_id="synthesis",
     )
 
     # Refresh global generation counter on page load/refresh
     demo.load(fn=refresh_counter_on_load, inputs=None, outputs=[generation_counter])
 
 if __name__ == "__main__":
-    demo.queue(max_size=5)
+    demo.queue(default_concurrency_limit=2, max_size=20)
     demo.launch(share=False, server_name="0.0.0.0", server_port=7860, debug=True)