Sync from v0.13

tests/v1/metrics/test_engine_logger_apis.py

@@ -0,0 +1,66 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import copy
+
+import pytest
+
+from tests.plugins.vllm_add_dummy_stat_logger.dummy_stat_logger.dummy_stat_logger import (  # noqa E501
+    DummyStatLogger,
+)
+from vllm.v1.engine.async_llm import AsyncEngineArgs, AsyncLLM
+from vllm.v1.metrics.ray_wrappers import RayPrometheusStatLogger
+
+
+@pytest.fixture
+def log_stats_enabled_engine_args():
+    """
+    Shared fixture providing common AsyncEngineArgs configuration
+    used across multiple tests.
+    """
+    return AsyncEngineArgs(
+        model="distilbert/distilgpt2",
+        dtype="half",
+        disable_log_stats=False,
+        enforce_eager=True,
+    )
+
+
+@pytest.mark.asyncio
+async def test_async_llm_replace_default_loggers(log_stats_enabled_engine_args):
+    """
+    RayPrometheusStatLogger should replace the default PrometheusStatLogger
+    """
+
+    engine = AsyncLLM.from_engine_args(
+        log_stats_enabled_engine_args, stat_loggers=[RayPrometheusStatLogger]
+    )
+    assert isinstance(engine.logger_manager.stat_loggers[0], RayPrometheusStatLogger)
+    engine.shutdown()
+
+
+@pytest.mark.asyncio
+async def test_async_llm_add_to_default_loggers(log_stats_enabled_engine_args):
+    """
+    It's still possible to use custom stat loggers exclusively by passing
+    disable_log_stats=True in addition to a list of custom stat loggers.
+    """
+    # Create engine_args with disable_log_stats=True for this test
+    disabled_log_engine_args = copy.deepcopy(log_stats_enabled_engine_args)
+    disabled_log_engine_args.disable_log_stats = True
+
+    # Disable default loggers; pass custom stat logger to the constructor
+    engine = AsyncLLM.from_engine_args(
+        disabled_log_engine_args, stat_loggers=[DummyStatLogger]
+    )
+
+    assert len(engine.logger_manager.stat_loggers) == 2
+    assert len(engine.logger_manager.stat_loggers[0].per_engine_stat_loggers) == 1
+    assert isinstance(
+        engine.logger_manager.stat_loggers[0].per_engine_stat_loggers[0],
+        DummyStatLogger,
+    )
+
+    # log_stats is still True, since custom stat loggers are used
+    assert engine.log_stats
+
+    engine.shutdown()