[python] warn up python model. (#23)

engines/python/setup/djl_python/inputs.py

@@ -150,6 +150,9 @@ def get_as_numpy(self, key=None) -> list:
         """
         return from_nd_list(self.get_as_bytes(key=key))
 
+    def is_empty(self):
+        return self.content.is_empty()
+
     def read(self, conn):
         prop_size = retrieve_short(conn)
 

engines/python/setup/djl_python/outputs.py

@@ -19,9 +19,9 @@
 
 
 class Output(object):
-    def __init__(self):
-        self.code = 200
-        self.message = 'OK'
+    def __init__(self, code=200, message='OK'):
+        self.code = code
+        self.message = message
         self.properties = dict()
         self.content = PairList()
 

engines/python/setup/djl_python_engine.py

@@ -84,12 +84,12 @@ def run_server(self):
             function_name = inputs.get_function_name()
             try:
                 outputs = getattr(self.service, function_name)(inputs)
+                if outputs is None:
+                    outputs = Output(code=204, message="No content")
             except Exception as e:
                 logging.error(e, exc_info=True)
                 _, ex_value, _ = sys.exc_info()
-                outputs = Output()
-                outputs.set_code(500)
-                outputs.set_message(str(ex_value))
+                outputs = Output(code=500, message=str(ex_value))
 
             if not cl_socket.sendall(outputs.encode()):
                 logging.debug("Outputs is sent to DJL engine.")

engines/python/src/main/java/ai/djl/python/engine/Connection.java

@@ -92,7 +92,7 @@ Output send(Input input) throws ExecutionException, InterruptedException, Timeou
             throw new IllegalStateException("Failed to send data to python.");
         }
         // TODO: make this configurable
-        return f.get(5, TimeUnit.MINUTES);
+        return f.get(10, TimeUnit.MINUTES);
     }
 
     private String[] getPythonStartCmd(PyEnv pyEnv, Model model) {

engines/python/src/main/java/ai/djl/python/engine/PyProcess.java

@@ -86,6 +86,13 @@ synchronized void startPythonProcess() {
             }
 
             connection.connect();
+
+            try {
+                // initialize model with an empty request
+                predict(new Input());
+            } catch (TranslateException ignore) {
+                logger.warn("Python model {} doesn't support warn up: ", model.getName());
+            }
         } catch (InterruptedException e) {
             throw new EngineException("Worker startup cancelled.", e);
         } catch (IOException e) {

engines/python/src/test/resources/accumulate/model.py

@@ -16,7 +16,8 @@
 
 import logging
 import numpy as np
-from djl_python import *
+from djl_python import Input
+from djl_python import Output
 
 
 class Accumulation(object):
@@ -65,7 +66,8 @@ def handle(inputs: Input):
         # stateful model
         _service.initialize(inputs.get_properties())
 
-    if inputs is None:
+    if inputs.is_empty():
+        # initialization request
         return None
 
     return _service.accumulate(inputs)

engines/python/src/test/resources/resnet18/model.py

@@ -146,7 +146,8 @@ def handle(inputs: Input):
         # stateful model
         _service.initialize(inputs.get_properties())
 
-    if inputs is None:
+    if inputs.is_empty():
+        # initialization request
         return None
 
     return _service.inference(inputs)