[Inference]Fix readme and example for API server (#5742)

* fix chatapi readme and example

* updating doc

* add an api and change the doc

* remove

* add credits and del 'API' heading

* readme

* readme

colossalai/inference/server/api_server.py

@@ -30,7 +30,6 @@ from colossalai.inference.utils import find_available_ports
 from colossalai.inference.core.async_engine import AsyncInferenceEngine, InferenceEngine  # noqa
 
 TIMEOUT_KEEP_ALIVE = 5  # seconds.
-supported_models_dict = {"Llama_Models": ("llama2-7b",)}
 prompt_template_choices = ["llama", "vicuna"]
 async_engine = None
 chat_serving = None
@@ -39,15 +38,25 @@ completion_serving = None
 app = FastAPI()
 
 
-# NOTE: (CjhHa1) models are still under development, need to be updated
-@app.get("/models")
-def get_available_models() -> Response:
-    return JSONResponse(supported_models_dict)
+@app.get("/ping")
+def health_check() -> JSONResponse:
+    """Health Check for server."""
+    return JSONResponse({"status": "Healthy"})
+
+
+@app.get("/engine_check")
+def engine_check() -> bool:
+    """Check if the background loop is running."""
+    loop_status = async_engine.background_loop_status
+    if loop_status == False:
+        return JSONResponse({"status": "Error"})
+    return JSONResponse({"status": "Running"})
 
 
 @app.post("/generate")
 async def generate(request: Request) -> Response:
     """Generate completion for the request.
+    NOTE: THIS API IS USED ONLY FOR TESTING, DO NOT USE THIS IF YOU ARE IN ACTUAL APPLICATION.
 
     A request should be a JSON object with the following fields:
     - prompts: the prompts to use for the generation.
@@ -133,7 +142,7 @@ def add_engine_config(parser):
     # Parallel arguments not supported now
 
     # KV cache arguments
-    parser.add_argument("--block-size", type=int, default=16, choices=[8, 16, 32], help="token block size")
+    parser.add_argument("--block_size", type=int, default=16, choices=[16, 32], help="token block size")
 
     parser.add_argument("--max_batch_size", type=int, default=8, help="maximum number of batch size")