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vllm.logging_utils.access_log_filter

Access log filter for uvicorn to exclude specific endpoints from logging.

This module provides a logging filter that can be used to suppress access logs for specific endpoints (e.g., /health, /metrics) to reduce log noise in production environments.

UvicornAccessLogFilter

Bases: Filter

A logging filter that excludes access logs for specified endpoint paths.

This filter is designed to work with uvicorn's access logger. It checks the log record's arguments for the request path and filters out records matching the excluded paths.

Uvicorn access log format

'%s - "%s %s HTTP/%s" %d' (client_addr, method, path, http_version, status_code)

Example

127.0.0.1:12345 - "GET /health HTTP/1.1" 200

Parameters:

Name Type Description Default
excluded_paths list[str] | None

A list of URL paths to exclude from logging. Paths are matched exactly. Example: ["/health", "/metrics"]

None
Source code in vllm/logging_utils/access_log_filter.py
class UvicornAccessLogFilter(logging.Filter):
    """
    A logging filter that excludes access logs for specified endpoint paths.

    This filter is designed to work with uvicorn's access logger. It checks
    the log record's arguments for the request path and filters out records
    matching the excluded paths.

    Uvicorn access log format:
        '%s - "%s %s HTTP/%s" %d'
        (client_addr, method, path, http_version, status_code)

    Example:
        127.0.0.1:12345 - "GET /health HTTP/1.1" 200

    Args:
        excluded_paths: A list of URL paths to exclude from logging.
                       Paths are matched exactly.
                       Example: ["/health", "/metrics"]
    """

    def __init__(self, excluded_paths: list[str] | None = None):
        super().__init__()
        self.excluded_paths = set(excluded_paths or [])

    def filter(self, record: logging.LogRecord) -> bool:
        """
        Determine if the log record should be logged.

        Args:
            record: The log record to evaluate.

        Returns:
            True if the record should be logged, False otherwise.
        """
        if not self.excluded_paths:
            return True

        # This filter is specific to uvicorn's access logs.
        if record.name != "uvicorn.access":
            return True

        # The path is the 3rd argument in the log record's args tuple.
        # See uvicorn's access logging implementation for details.
        log_args = record.args
        if isinstance(log_args, tuple) and len(log_args) >= 3:
            path_with_query = log_args[2]
            # Get path component without query string.
            if isinstance(path_with_query, str):
                path = urlparse(path_with_query).path
                if path in self.excluded_paths:
                    return False

        return True

excluded_paths instance-attribute

excluded_paths = set(excluded_paths or [])

__init__

__init__(excluded_paths: list[str] | None = None)
Source code in vllm/logging_utils/access_log_filter.py
def __init__(self, excluded_paths: list[str] | None = None):
    super().__init__()
    self.excluded_paths = set(excluded_paths or [])

filter

filter(record: LogRecord) -> bool

Determine if the log record should be logged.

Parameters:

Name Type Description Default
record LogRecord

The log record to evaluate.

required

Returns:

Type Description
bool

True if the record should be logged, False otherwise.

Source code in vllm/logging_utils/access_log_filter.py
def filter(self, record: logging.LogRecord) -> bool:
    """
    Determine if the log record should be logged.

    Args:
        record: The log record to evaluate.

    Returns:
        True if the record should be logged, False otherwise.
    """
    if not self.excluded_paths:
        return True

    # This filter is specific to uvicorn's access logs.
    if record.name != "uvicorn.access":
        return True

    # The path is the 3rd argument in the log record's args tuple.
    # See uvicorn's access logging implementation for details.
    log_args = record.args
    if isinstance(log_args, tuple) and len(log_args) >= 3:
        path_with_query = log_args[2]
        # Get path component without query string.
        if isinstance(path_with_query, str):
            path = urlparse(path_with_query).path
            if path in self.excluded_paths:
                return False

    return True

create_uvicorn_log_config

create_uvicorn_log_config(
    excluded_paths: list[str] | None = None,
    log_level: str = "info",
) -> dict

Create a uvicorn logging configuration with access log filtering.

This function generates a logging configuration dictionary that can be passed to uvicorn's log_config parameter. It sets up the access log filter to exclude specified paths.

Parameters:

Name Type Description Default
excluded_paths list[str] | None

List of URL paths to exclude from access logs.

None
log_level str

The log level for uvicorn loggers.

'info'

Returns:

Type Description
dict

A dictionary containing the logging configuration.

Example

config = create_uvicorn_log_config(["/health", "/metrics"]) uvicorn.run(app, log_config=config)

Source code in vllm/logging_utils/access_log_filter.py
def create_uvicorn_log_config(
    excluded_paths: list[str] | None = None,
    log_level: str = "info",
) -> dict:
    """
    Create a uvicorn logging configuration with access log filtering.

    This function generates a logging configuration dictionary that can be
    passed to uvicorn's `log_config` parameter. It sets up the access log
    filter to exclude specified paths.

    Args:
        excluded_paths: List of URL paths to exclude from access logs.
        log_level: The log level for uvicorn loggers.

    Returns:
        A dictionary containing the logging configuration.

    Example:
        >>> config = create_uvicorn_log_config(["/health", "/metrics"])
        >>> uvicorn.run(app, log_config=config)
    """
    config = {
        "version": 1,
        "disable_existing_loggers": False,
        "filters": {
            "access_log_filter": {
                "()": UvicornAccessLogFilter,
                "excluded_paths": excluded_paths or [],
            },
        },
        "formatters": {
            "default": {
                "()": "uvicorn.logging.DefaultFormatter",
                "fmt": "%(levelprefix)s %(message)s",
                "use_colors": None,
            },
            "access": {
                "()": "uvicorn.logging.AccessFormatter",
                "fmt": '%(levelprefix)s %(client_addr)s - "%(request_line)s" %(status_code)s',  # noqa: E501
            },
        },
        "handlers": {
            "default": {
                "formatter": "default",
                "class": "logging.StreamHandler",
                "stream": "ext://sys.stderr",
            },
            "access": {
                "formatter": "access",
                "class": "logging.StreamHandler",
                "stream": "ext://sys.stdout",
                "filters": ["access_log_filter"],
            },
        },
        "loggers": {
            "uvicorn": {
                "handlers": ["default"],
                "level": log_level.upper(),
                "propagate": False,
            },
            "uvicorn.error": {
                "level": log_level.upper(),
                "handlers": ["default"],
                "propagate": False,
            },
            "uvicorn.access": {
                "handlers": ["access"],
                "level": log_level.upper(),
                "propagate": False,
            },
        },
    }
    return config