Fix bench_serving with random-ids (#5214)

python/sglang/bench_serving.py

@@ -490,7 +490,7 @@ def get_dataset(args, tokenizer):
             prompt_suffix=args.prompt_suffix,
             apply_chat_template=args.apply_chat_template,
         )
-    elif args.dataset_name == "random":
+    elif args.dataset_name.startswith("random"):
         input_requests = sample_random_requests(
             input_len=args.random_input_len,
             output_len=args.random_output_len,
@@ -498,6 +498,7 @@ def get_dataset(args, tokenizer):
             range_ratio=args.random_range_ratio,
             tokenizer=tokenizer,
             dataset_path=args.dataset_path,
+            random_sample=args.dataset_name == "random",
         )
     elif args.dataset_name == "generated-shared-prefix":
         input_requests = sample_generated_shared_prefix_requests(
@@ -687,6 +688,7 @@ def sample_random_requests(
     range_ratio: float,
     tokenizer: PreTrainedTokenizerBase,
     dataset_path: str,
+    random_sample: bool = True,
 ) -> List[Tuple[str, int, int]]:
 
     input_lens = np.random.randint(
@@ -700,11 +702,15 @@ def sample_random_requests(
         size=num_prompts,
     )
 
-    if True:
+    if random_sample:
         # Sample token ids from ShareGPT and repeat/truncate them to satisfy the input_lens
 
         # Download sharegpt if necessary
         if not os.path.isfile(dataset_path):
+            print(
+                "If you do not want to randomly sample from a dataset,"
+                " please use --dataset-name random-ids."
+            )
             dataset_path = download_and_cache_file(SHAREGPT_URL)
 
         # Load the dataset.
@@ -1223,7 +1229,7 @@ async def benchmark(
         output_file_name = args.output_file
     else:
         now = datetime.now().strftime("%m%d")
-        if args.dataset_name == "random":
+        if args.dataset_name.startswith("random"):
             output_file_name = f"{args.backend}_{now}_{args.num_prompts}_{args.random_input_len}_{args.random_output_len}.jsonl"
         else:
             output_file_name = f"{args.backend}_{now}_{args.num_prompts}_sharegpt.jsonl"
@@ -1442,7 +1448,7 @@ if __name__ == "__main__":
         "--dataset-name",
         type=str,
         default="sharegpt",
-        choices=["sharegpt", "random", "generated-shared-prefix"],
+        choices=["sharegpt", "random", "random-ids", "generated-shared-prefix"],
         help="Name of the dataset to benchmark on.",
     )
     parser.add_argument(