Fix logging issues

[Tostino]

Currently, info logs are not actually being logged.

For example the args log in the OpenAI api_server:

logger.info(f"args: {args}")

doesn't actually print anything when you start the server.

This pull request fixes that.

[zhuohan123]

Thanks for fixing this!! I was confused about the behavior of this logger for a while and met the issue that I could not print logs from the openai API server.

[WoosukKwon]

@Tostino @zhuohan123 It seems this PR makes the logs printed twice:

$ python examples/llm_engine_example.py 
INFO 10-31 15:40:46 llm_engine.py:72] Initializing an LLM engine with config: model='facebook/opt-125m', tokenizer='facebook/opt-125m', tokenizer_mode=auto, revision=None, tokenizer_revision=None, trust_remote_code=False, dtype=torch.float16, max_seq_len=2048, download_dir=None, load_format=auto, tensor_parallel_size=1, quantization=None, seed=0)
INFO 10-31 15:40:46 llm_engine.py:72] Initializing an LLM engine with config: model='facebook/opt-125m', tokenizer='facebook/opt-125m', tokenizer_mode=auto, revision=None, tokenizer_revision=None, trust_remote_code=False, dtype=torch.float16, max_seq_len=2048, download_dir=None, load_format=auto, tensor_parallel_size=1, quantization=None, seed=0)
INFO 10-31 15:40:52 llm_engine.py:207] # GPU blocks: 127960, # CPU blocks: 7281
INFO 10-31 15:40:52 llm_engine.py:207] # GPU blocks: 127960, # CPU blocks: 7281

[Tostino]

Hmm, is that with multiple GPUs that it is happening? Does it happen with a single GPU if so?

I'd check myself, but I'm out of town right now and don't have a machine I can test on locally.