Implementation:LMCache LMCache Logging

Knowledge Sources	LMCache
Domains	Logging, Observability
Last Updated	2026-02-09 00:00 GMT

Overview

Provides a custom color-coded logging framework for LMCache with configurable log levels via environment variables.

Description

This module defines a CustomFormatter that applies ANSI color codes to log messages based on severity level: grey for DEBUG, green for INFO, yellow for WARNING, red for ERROR, and bold red for CRITICAL. Each log line includes a timestamp, the "LMCache" prefix, the log level, the message, and an italicized source location (filename, line number, logger name). The init_logger function creates isolated loggers with no propagation to parent loggers. Log level is controlled by the LMCACHE_LOG_LEVEL environment variable, defaulting to INFO.

Usage

Call init_logger(__name__) at the top of any LMCache module to obtain a properly configured logger instance. Set the LMCACHE_LOG_LEVEL environment variable to DEBUG, INFO, WARNING, ERROR, or CRITICAL to control verbosity.

Code Reference

Source Location

• Repository: LMCache
• File: lmcache/logging.py
• Lines: 1-96

Signature

def build_format(color: str) -> str: ...

class CustomFormatter(logging.Formatter):
    def format(self, record) -> str: ...

def get_log_level() -> int: ...

def init_logger(name: str) -> Logger: ...

Import

from lmcache.logging import init_logger

I/O Contract

Inputs

Name	Type	Required	Description
name	str	Yes	Logger name, typically __name__ of the calling module
LMCACHE_LOG_LEVEL	env var	No	Environment variable to set log level (default: INFO)

Outputs

Name	Type	Description
logger	logging.Logger	Configured logger with color-coded console output and no parent propagation

Usage Examples

from lmcache.logging import init_logger

logger = init_logger(__name__)

logger.debug("Detailed debugging information")
logger.info("Cache engine initialized successfully")
logger.warning("Cache miss rate exceeding threshold")
logger.error("Failed to connect to remote storage")