[docs] Enhance vLLM health check docs

Author: kthui

README.md

@@ -316,31 +316,11 @@ parameters: {
 }
 ```
 
-## vLLM Health Check (BETA)
+## vLLM Engine Health Check (BETA)
 
-> [!NOTE]
-> The vLLM Health Check feature is currently in BETA. Its features and
-> functionality are subject to change as we collect feedback. We are excited to
-> hear any thoughts you have!
-
-The vLLM backend supports checking for
-[vLLM Engine Health](https://github.com/vllm-project/vllm/blob/v0.6.3.post1/vllm/engine/async_llm_engine.py#L1177-L1185)
-when an inference request is received. If the health check fails, the entire
-model will be unloaded, so it becomes NOT Ready at the server.
-
-The Health Check is disabled by default. To enable it, set the following
-parameter on the model config to true
-```
-parameters: {
-  key: "ENABLE_VLLM_HEALTH_CHECK"
-  value: { string_value: "true" }
-}
-```
-and select
-[Model Control Mode EXPLICIT](https://github.com/triton-inference-server/server/blob/main/docs/user_guide/model_management.md#model-control-mode-explicit)
-when the server is started.
-
-Supported since r24.12.
+vLLM Engine Health Check may be enabled optionally, for more accurate model
+state reported by the server. See [this docs](docs/health_check.md) for more
+information.
 
 ## Referencing the Tutorial
 

docs/health_check.md

@@ -0,0 +1,58 @@
+<!--
+# Copyright 2024, 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.
+-->
+
+# vLLM Health Check (BETA)
+
+> [!NOTE]
+> The vLLM Health Check support is currently in BETA. Its features and
+> functionality are subject to change as we collect feedback. We are excited to
+> hear any thoughts you have!
+
+The vLLM backend supports checking for
+[vLLM Engine Health](https://github.com/vllm-project/vllm/blob/v0.6.3.post1/vllm/engine/async_llm_engine.py#L1177-L1185)
+upon receiving each inference request. If the health check fails, the entire
+model will be unloaded, so its state becomes NOT Ready at the server, which can
+be queried by the
+[Repository Index](https://github.com/triton-inference-server/server/blob/main/docs/protocol/extension_model_repository.md#index)
+or
+[Model Ready](https://github.com/triton-inference-server/client/blob/main/src/c%2B%2B/library/http_client.h#L178-L192)
+APIs.
+
+The Health Check is disabled by default. To enable it, set the following
+parameter on the model config to true
+```
+parameters: {
+  key: "ENABLE_VLLM_HEALTH_CHECK"
+  value: { string_value: "true" }
+}
+```
+and select
+[Model Control Mode EXPLICIT](https://github.com/triton-inference-server/server/blob/main/docs/user_guide/model_management.md#model-control-mode-explicit)
+when the server is started.
+
+Supported since r24.12.