log.md

heflwr.log

heflwr.log module is responsible for logging and tracing the running status of the entire project. This module provides three components: logger, log, and configure.

logger

logger is a logging.Logger object with the name hetero-flwr. It is a global logger (per-project logger) and can be used like a common logging.Logger object. For example:

from heflwr.log import logger

logger.debug("hello, world!")
logger.info("hello, world!")
logger.warning("hello, world!")
logger.error("hello, world!")
logger.critical("hello, world!")

The logger object is by default bound to logging.StreamHandler(stream=sys.stdout), so the above example will print logs containing "hello, world!" to the standard output.

log

The log method of the logger provides a quick way to log messages directly. It is equivalent to the global logger's log method. You only need to pass the log level and the message, for example:

from logging import INFO
from heflwr.log import log

log(INFO, "hello, world!")

The example above will print a log with the message "hello, world!" to the standard output.

configure

The configure function is used to customize the behavior of the global logger, such as specifying log identifiers, output file paths, and remote HTTP server addresses. It accepts the following parameters:

• identifier: str: A string identifier that will be added as a prefix to each log entry to help trace the source of the log. A typical use is to set it as a client identifier, such as "client-A", to indicate the source of the log to a remote server.
• file: Optional[str] = None: An optional parameter for specifying the path to the log output file. If provided, logs will be written to this file as well.
• host: Optional[str] = None: An optional parameter for specifying the address of a remote HTTP server. If provided, logs will be sent to this server.
• simple: Optional[bool] = None: An optional parameter that specifies the format of remote logs. This parameter must be used in conjunction with the host parameter. If the host parameter is set to None, specifying the simple parameter will raise a warning. If host is not None and simple is set to None or False, logs will be sent in standard format to the /log URL of the remote server. If host is not None and simple is set to True, logs will be sent in a concise format to the /simple_log URL of the remote server to reduce network transmission overhead.

Calling the configure function can add FileHandler and/or HTTPHandler to the global logger, for example:

from heflwr.log import logger, configure

configure(identifier="my-app", file="logs/app.log")
configure(identifier="client-A", host="127.0.0.1:5000")
configure(identifier="client-A", file="logs/app.log", host="127.0.0.1:5000")
configure(identifier="client-A", file="logs/app.log", host="127.0.0.1:5000", simple=True)

logger.info("hello, world!")

By doing this, logs can not only be output to the standard output but also to the corresponding file and/or HTTP server.