Sync v2.0 version of code to github repo

docs/usage/log.md

@@ -0,0 +1,38 @@
+# Log Description
+
+FastDeploy generates the following log files during deployment. Below is an explanation of each log's purpose.  
+By default, logs are stored in the `log` directory under the execution path. To specify a custom directory, set the environment variable `FD_LOG_DIR`.
+
+## Inference Service Logs
+* `backup_env.*.json` : Records environment variables set during instance startup. The number of files matches the number of GPU cards.
+* `envlog.*` : Logs environment variables set during instance startup. The number of files matches the number of GPU cards.
+* `console.log` : Records model startup time and other information. This log is also printed to the console.
+* `data_processor.log` : Logs input/output data encoding and decoding details.
+* `fastdeploy.log` : Records configuration information during instance startup, as well as request and response details during runtime.
+* `workerlog.*` : Tracks model loading progress and inference operator errors. Each GPU card has a corresponding file.
+* `worker_process.log` : Logs engine inference data for each iteration.
+* `prefix_cache_manager.log` : Records KV Cache logical index allocation for each request and cache hit status.
+* `launch_worker.log` : Logs model startup information and error messages.
+* `gpu_worker.log` : Records KV Cache block count information during profiling.
+* `gpu_model_runner.log` : Contains model details and loading time.
+
+## Online Inference Client Logs
+* `api_server.log` : Logs startup parameters and received request information.
+
+## Scheduler Logs
+* `scheduler.log` : Records scheduler information, including node status and request allocation details.
+
+## Speculative Decoding Logs
+* `speculate.log` : Contains speculative decoding-related information.
+
+## Prefix Caching Logs
+* `cache_queue_manager.log` : Logs startup parameters and received request information.
+* `cache_transfer_manager.log` : Logs startup parameters and received request information.
+* `launch_cache_manager.log` : Records cache transfer startup parameters and error messages.
+
+## PD Disaggragation Logs
+* `cache_messager.log` : Logs transmission protocols and messages used by the P instance.
+* `splitwise_connector.log` : Records data received from P/D instances and connection establishment details.
+
+## CudaGraph Logs
+* `cudagraph_piecewise_backend.log` : Logs CudaGraph startup and error information.