Add test for delayed model startups in PB (triton-inference-server#3095)

* Add test for delayed model startups in PB

* Review edits

qa/L0_backend_python/test.sh

@@ -75,6 +75,10 @@ cp ../python_models/pytorch_fp32_fp32/config.pbtxt ./models/pytorch_fp32_fp32/
 (cd models/pytorch_fp32_fp32 && \
           sed -i "s/^name:.*/name: \"pytorch_fp32_fp32\"/" config.pbtxt)
 
+mkdir -p models/delayed_model/1/
+cp -r ../python_models/delayed_model/model.py ./models/delayed_model/1/
+cp ../python_models/delayed_model/config.pbtxt ./models/delayed_model/
+
 mkdir -p models/init_args/1/
 cp ../python_models/init_args/model.py ./models/init_args/1/
 cp ../python_models/init_args/config.pbtxt ./models/init_args/

qa/python_models/delayed_model/config.pbtxt

@@ -0,0 +1,52 @@
+# Copyright 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of NVIDIA CORPORATION nor the names of its
+#    contributors may be used to endorse or promote products derived
+#    from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+name: "delayed_model"
+backend: "python"
+max_batch_size: 64
+
+input [
+  {
+    name: "IN"
+    data_type: TYPE_FP32
+    dims: [ -1 ]
+  }
+]
+
+output [
+  {
+    name: "OUT"
+    data_type: TYPE_FP32
+    dims: [ -1 ]
+  }
+]
+
+instance_group [
+  {
+    count: 1
+    kind : KIND_CPU
+  }
+]

qa/python_models/delayed_model/model.py

@@ -0,0 +1,45 @@
+# Copyright 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of NVIDIA CORPORATION nor the names of its
+#    contributors may be used to endorse or promote products derived
+#    from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import triton_python_backend_utils as pb_utils
+import time
+
+# Sleep for 5 seconds to ensure that delayed startup works properly.
+time.sleep(5)
+
+
+class TritonPythonModel:
+
+    def execute(self, requests):
+        responses = []
+        for request in requests:
+            input_tensor = pb_utils.get_input_tensor_by_name(request, "IN")
+            out_tensor = utils.Tensor("OUT", input_tensor.as_numpy())
+            responses.append(utils.InferenceResponse([out_tensor]))
+        return responses
+
+    def finalize(self):
+        pass