# SOME DESCRIPTIVE TITLE.

# Copyright (C) 2001-2026, Python Software Foundation

# This file is distributed under the same license as the Python package.

# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.

#

# Translators:

# python-doc bot, 2025

#

#, fuzzy

msgid ""

msgstr ""

"Project-Id-Version: Python 3.13\n"

"Report-Msgid-Bugs-To: \n"

"POT-Creation-Date: 2026-04-11 15:18+0000\n"

"PO-Revision-Date: 2025-09-15 01:03+0000\n"

"Last-Translator: python-doc bot, 2025\n"

"Language-Team: Polish (https://app.transifex.com/python-doc/teams/5390/pl/)\n"

"MIME-Version: 1.0\n"

"Content-Type: text/plain; charset=UTF-8\n"

"Content-Transfer-Encoding: 8bit\n"

"Language: pl\n"

"Plural-Forms: nplurals=4; plural=(n==1 ? 0 : (n%10>=2 && n%10<=4) && "

"(n%100<12 || n%100>14) ? 1 : n!=1 && (n%10>=0 && n%10<=1) || (n%10>=5 && "

"n%10<=9) || (n%100>=12 && n%100<=14) ? 2 : 3);\n"

msgid "Logging Cookbook"

msgstr ""

msgid "Author"

msgstr "Autor"

msgid "Vinay Sajip <vinay_sajip at red-dove dot com>"

msgstr ""

msgid ""

"This page contains a number of recipes related to logging, which have been "

"found useful in the past. For links to tutorial and reference information, "

"please see :ref:`cookbook-ref-links`."

msgstr ""

msgid "Using logging in multiple modules"

msgstr ""

msgid ""

"Multiple calls to ``logging.getLogger('someLogger')`` return a reference to "

"the same logger object. This is true not only within the same module, but "

"also across modules as long as it is in the same Python interpreter "

"process. It is true for references to the same object; additionally, "

"application code can define and configure a parent logger in one module and "

"create (but not configure) a child logger in a separate module, and all "

"logger calls to the child will pass up to the parent. Here is a main "

"module::"

msgstr ""

msgid ""

"import logging\n"

"import auxiliary_module\n"

"\n"

"# create logger with 'spam_application'\n"

"logger = logging.getLogger('spam_application')\n"

"logger.setLevel(logging.DEBUG)\n"

"# create file handler which logs even debug messages\n"

"fh = logging.FileHandler('spam.log')\n"

"fh.setLevel(logging.DEBUG)\n"

"# create console handler with a higher log level\n"

"ch = logging.StreamHandler()\n"

"ch.setLevel(logging.ERROR)\n"

"# create formatter and add it to the handlers\n"

"formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - "

"%(message)s')\n"

"fh.setFormatter(formatter)\n"

"ch.setFormatter(formatter)\n"

"# add the handlers to the logger\n"

"logger.addHandler(fh)\n"

"logger.addHandler(ch)\n"

"\n"

"logger.info('creating an instance of auxiliary_module.Auxiliary')\n"

"a = auxiliary_module.Auxiliary()\n"

"logger.info('created an instance of auxiliary_module.Auxiliary')\n"

"logger.info('calling auxiliary_module.Auxiliary.do_something')\n"

"a.do_something()\n"

"logger.info('finished auxiliary_module.Auxiliary.do_something')\n"

"logger.info('calling auxiliary_module.some_function()')\n"

"auxiliary_module.some_function()\n"

"logger.info('done with auxiliary_module.some_function()')"

msgstr ""

msgid "Here is the auxiliary module::"

msgstr ""

msgid ""

"import logging\n"

"\n"

"# create logger\n"

"module_logger = logging.getLogger('spam_application.auxiliary')\n"

"\n"

"class Auxiliary:\n"

" def __init__(self):\n"

" self.logger = logging.getLogger('spam_application.auxiliary."

"Auxiliary')\n"

" self.logger.info('creating an instance of Auxiliary')\n"

"\n"

" def do_something(self):\n"

" self.logger.info('doing something')\n"

" a = 1 + 1\n"

" self.logger.info('done doing something')\n"

"\n"

"def some_function():\n"

" module_logger.info('received a call to \"some_function\"')"

msgstr ""

msgid "The output looks like this:"

msgstr "Wynik wygląda tak:"

msgid ""

"2005-03-23 23:47:11,663 - spam_application - INFO -\n"

" creating an instance of auxiliary_module.Auxiliary\n"

"2005-03-23 23:47:11,665 - spam_application.auxiliary.Auxiliary - INFO -\n"

" creating an instance of Auxiliary\n"

"2005-03-23 23:47:11,665 - spam_application - INFO -\n"

" created an instance of auxiliary_module.Auxiliary\n"

"2005-03-23 23:47:11,668 - spam_application - INFO -\n"

" calling auxiliary_module.Auxiliary.do_something\n"

"2005-03-23 23:47:11,668 - spam_application.auxiliary.Auxiliary - INFO -\n"

" doing something\n"

"2005-03-23 23:47:11,669 - spam_application.auxiliary.Auxiliary - INFO -\n"

" done doing something\n"

"2005-03-23 23:47:11,670 - spam_application - INFO -\n"

" finished auxiliary_module.Auxiliary.do_something\n"

"2005-03-23 23:47:11,671 - spam_application - INFO -\n"

" calling auxiliary_module.some_function()\n"

"2005-03-23 23:47:11,672 - spam_application.auxiliary - INFO -\n"

" received a call to 'some_function'\n"

"2005-03-23 23:47:11,673 - spam_application - INFO -\n"

" done with auxiliary_module.some_function()"

msgstr ""

msgid "Logging from multiple threads"

msgstr ""

msgid ""

"Logging from multiple threads requires no special effort. The following "

"example shows logging from the main (initial) thread and another thread::"

msgstr ""

msgid ""

"import logging\n"

"import threading\n"

"import time\n"

"\n"

"def worker(arg):\n"

" while not arg['stop']:\n"

" logging.debug('Hi from myfunc')\n"

" time.sleep(0.5)\n"

"\n"

"def main():\n"

" logging.basicConfig(level=logging.DEBUG, format='%(relativeCreated)6d "

"%(threadName)s %(message)s')\n"

" info = {'stop': False}\n"

" thread = threading.Thread(target=worker, args=(info,))\n"

" thread.start()\n"

" while True:\n"

" try:\n"

" logging.debug('Hello from main')\n"

" time.sleep(0.75)\n"

" except KeyboardInterrupt:\n"

" info['stop'] = True\n"

" break\n"

" thread.join()\n"

"\n"

"if __name__ == '__main__':\n"

" main()"

msgstr ""

msgid "When run, the script should print something like the following:"

msgstr ""

msgid ""

" 0 Thread-1 Hi from myfunc\n"

" 3 MainThread Hello from main\n"

" 505 Thread-1 Hi from myfunc\n"

" 755 MainThread Hello from main\n"

"1007 Thread-1 Hi from myfunc\n"

"1507 MainThread Hello from main\n"

"1508 Thread-1 Hi from myfunc\n"

"2010 Thread-1 Hi from myfunc\n"

"2258 MainThread Hello from main\n"

"2512 Thread-1 Hi from myfunc\n"

"3009 MainThread Hello from main\n"

"3013 Thread-1 Hi from myfunc\n"

"3515 Thread-1 Hi from myfunc\n"

"3761 MainThread Hello from main\n"

"4017 Thread-1 Hi from myfunc\n"

"4513 MainThread Hello from main\n"

"4518 Thread-1 Hi from myfunc"

msgstr ""

msgid ""

"This shows the logging output interspersed as one might expect. This "

"approach works for more threads than shown here, of course."

msgstr ""

msgid "Multiple handlers and formatters"

msgstr ""

msgid ""

"Loggers are plain Python objects. The :meth:`~Logger.addHandler` method has "

"no minimum or maximum quota for the number of handlers you may add. "

"Sometimes it will be beneficial for an application to log all messages of "

"all severities to a text file while simultaneously logging errors or above "

"to the console. To set this up, simply configure the appropriate handlers. "

"The logging calls in the application code will remain unchanged. Here is a "

"slight modification to the previous simple module-based configuration "

"example::"

msgstr ""

msgid ""

"import logging\n"

"\n"

"logger = logging.getLogger('simple_example')\n"

"logger.setLevel(logging.DEBUG)\n"

"# create file handler which logs even debug messages\n"

"fh = logging.FileHandler('spam.log')\n"

"fh.setLevel(logging.DEBUG)\n"

"# create console handler with a higher log level\n"

"ch = logging.StreamHandler()\n"

"ch.setLevel(logging.ERROR)\n"

"# create formatter and add it to the handlers\n"

"formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - "

"%(message)s')\n"

"ch.setFormatter(formatter)\n"

"fh.setFormatter(formatter)\n"

"# add the handlers to logger\n"

"logger.addHandler(ch)\n"

"logger.addHandler(fh)\n"

"\n"

"# 'application' code\n"

"logger.debug('debug message')\n"

"logger.info('info message')\n"

"logger.warning('warn message')\n"

"logger.error('error message')\n"

"logger.critical('critical message')"

msgstr ""

msgid ""

"Notice that the 'application' code does not care about multiple handlers. "

"All that changed was the addition and configuration of a new handler named "

"*fh*."

msgstr ""

msgid ""

"The ability to create new handlers with higher- or lower-severity filters "

"can be very helpful when writing and testing an application. Instead of "

"using many ``print`` statements for debugging, use ``logger.debug``: Unlike "

"the print statements, which you will have to delete or comment out later, "

"the logger.debug statements can remain intact in the source code and remain "

"dormant until you need them again. At that time, the only change that needs "

"to happen is to modify the severity level of the logger and/or handler to "

"debug."

msgstr ""

msgid "Logging to multiple destinations"

msgstr ""

msgid ""

"Let's say you want to log to console and file with different message formats "

"and in differing circumstances. Say you want to log messages with levels of "

"DEBUG and higher to file, and those messages at level INFO and higher to the "

"console. Let's also assume that the file should contain timestamps, but the "

"console messages should not. Here's how you can achieve this::"

msgstr ""

msgid ""

"import logging\n"

"\n"

"# set up logging to file - see previous section for more details\n"

"logging.basicConfig(level=logging.DEBUG,\n"

" format='%(asctime)s %(name)-12s %(levelname)-8s "

"%(message)s',\n"

" datefmt='%m-%d %H:%M',\n"

" filename='/tmp/myapp.log',\n"

" filemode='w')\n"

"# define a Handler which writes INFO messages or higher to the sys.stderr\n"

"console = logging.StreamHandler()\n"

"console.setLevel(logging.INFO)\n"

"# set a format which is simpler for console use\n"

"formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')\n"

"# tell the handler to use this format\n"

"console.setFormatter(formatter)\n"

"# add the handler to the root logger\n"

"logging.getLogger().addHandler(console)\n"

"\n"

"# Now, we can log to the root logger, or any other logger. First the "

"root...\n"

"logging.info('Jackdaws love my big sphinx of quartz.')\n"

"\n"

"# Now, define a couple of other loggers which might represent areas in your\n"

"# application:\n"

"\n"

"logger1 = logging.getLogger('myapp.area1')\n"

"logger2 = logging.getLogger('myapp.area2')\n"

"\n"

"logger1.debug('Quick zephyrs blow, vexing daft Jim.')\n"

"logger1.info('How quickly daft jumping zebras vex.')\n"

"logger2.warning('Jail zesty vixen who grabbed pay from quack.')\n"

"logger2.error('The five boxing wizards jump quickly.')"

msgstr ""

msgid "When you run this, on the console you will see"

msgstr ""

msgid ""

"root : INFO Jackdaws love my big sphinx of quartz.\n"

"myapp.area1 : INFO How quickly daft jumping zebras vex.\n"

"myapp.area2 : WARNING Jail zesty vixen who grabbed pay from quack.\n"

"myapp.area2 : ERROR The five boxing wizards jump quickly."

msgstr ""

msgid "and in the file you will see something like"

msgstr ""

msgid ""

"10-22 22:19 root INFO Jackdaws love my big sphinx of quartz.\n"

"10-22 22:19 myapp.area1 DEBUG Quick zephyrs blow, vexing daft Jim.\n"

"10-22 22:19 myapp.area1 INFO How quickly daft jumping zebras vex.\n"

"10-22 22:19 myapp.area2 WARNING Jail zesty vixen who grabbed pay from "

"quack.\n"

"10-22 22:19 myapp.area2 ERROR The five boxing wizards jump quickly."

msgstr ""

msgid ""

"As you can see, the DEBUG message only shows up in the file. The other "

"messages are sent to both destinations."

msgstr ""

msgid ""

"This example uses console and file handlers, but you can use any number and "

"combination of handlers you choose."

msgstr ""

msgid ""

"Note that the above choice of log filename ``/tmp/myapp.log`` implies use of "

"a standard location for temporary files on POSIX systems. On Windows, you "

"may need to choose a different directory name for the log - just ensure that "

"the directory exists and that you have the permissions to create and update "

"files in it."

msgstr ""

msgid "Custom handling of levels"

msgstr ""

msgid ""

"Sometimes, you might want to do something slightly different from the "

"standard handling of levels in handlers, where all levels above a threshold "

"get processed by a handler. To do this, you need to use filters. Let's look "

"at a scenario where you want to arrange things as follows:"

msgstr ""

msgid "Send messages of severity ``INFO`` and ``WARNING`` to ``sys.stdout``"

msgstr ""

msgid "Send messages of severity ``ERROR`` and above to ``sys.stderr``"

msgstr ""

msgid "Send messages of severity ``DEBUG`` and above to file ``app.log``"

msgstr ""

msgid "Suppose you configure logging with the following JSON:"

msgstr ""

msgid ""

"{\n"

" \"version\": 1,\n"

" \"disable_existing_loggers\": false,\n"

" \"formatters\": {\n"

" \"simple\": {\n"

" \"format\": \"%(levelname)-8s - %(message)s\"\n"

" }\n"

" },\n"

" \"handlers\": {\n"

" \"stdout\": {\n"

" \"class\": \"logging.StreamHandler\",\n"

" \"level\": \"INFO\",\n"

" \"formatter\": \"simple\",\n"

" \"stream\": \"ext://sys.stdout\"\n"

" },\n"

" \"stderr\": {\n"

" \"class\": \"logging.StreamHandler\",\n"

" \"level\": \"ERROR\",\n"

" \"formatter\": \"simple\",\n"

" \"stream\": \"ext://sys.stderr\"\n"

" },\n"

" \"file\": {\n"

" \"class\": \"logging.FileHandler\",\n"

" \"formatter\": \"simple\",\n"

" \"filename\": \"app.log\",\n"

" \"mode\": \"w\"\n"

" }\n"

" },\n"

" \"root\": {\n"

" \"level\": \"DEBUG\",\n"

" \"handlers\": [\n"

" \"stderr\",\n"

" \"stdout\",\n"

" \"file\"\n"

" ]\n"

" }\n"

"}"

msgstr ""

msgid ""

"This configuration does *almost* what we want, except that ``sys.stdout`` "

"would show messages of severity ``ERROR`` and only events of this severity "

"and higher will be tracked as well as ``INFO`` and ``WARNING`` messages. To "

"prevent this, we can set up a filter which excludes those messages and add "

"it to the relevant handler. This can be configured by adding a ``filters`` "

"section parallel to ``formatters`` and ``handlers``:"

msgstr ""

msgid ""

"{\n"

" \"filters\": {\n"

" \"warnings_and_below\": {\n"

" \"()\" : \"__main__.filter_maker\",\n"

" \"level\": \"WARNING\"\n"

" }\n"

" }\n"

"}"

msgstr ""

msgid "and changing the section on the ``stdout`` handler to add it:"

msgstr ""

msgid ""

"{\n"

" \"stdout\": {\n"

" \"class\": \"logging.StreamHandler\",\n"

" \"level\": \"INFO\",\n"

" \"formatter\": \"simple\",\n"

" \"stream\": \"ext://sys.stdout\",\n"

" \"filters\": [\"warnings_and_below\"]\n"

" }\n"

"}"

msgstr ""

msgid ""

"A filter is just a function, so we can define the ``filter_maker`` (a "

"factory function) as follows:"

msgstr ""

msgid ""

"def filter_maker(level):\n"

" level = getattr(logging, level)\n"

"\n"

" def filter(record):\n"

" return record.levelno <= level\n"

"\n"

" return filter"

msgstr ""

msgid ""

"This converts the string argument passed in to a numeric level, and returns "

"a function which only returns ``True`` if the level of the passed in record "

"is at or below the specified level. Note that in this example I have defined "

"the ``filter_maker`` in a test script ``main.py`` that I run from the "

"command line, so its module will be ``__main__`` - hence the ``__main__."

"filter_maker`` in the filter configuration. You will need to change that if "

"you define it in a different module."

msgstr ""

msgid "With the filter added, we can run ``main.py``, which in full is:"

msgstr ""

msgid ""

"import json\n"

"import logging\n"

"import logging.config\n"

"\n"

"CONFIG = '''\n"

"{\n"

" \"version\": 1,\n"

" \"disable_existing_loggers\": false,\n"

" \"formatters\": {\n"

" \"simple\": {\n"

" \"format\": \"%(levelname)-8s - %(message)s\"\n"

" }\n"

" },\n"

" \"filters\": {\n"

" \"warnings_and_below\": {\n"

" \"()\" : \"__main__.filter_maker\",\n"

" \"level\": \"WARNING\"\n"

" }\n"

" },\n"

" \"handlers\": {\n"

" \"stdout\": {\n"

" \"class\": \"logging.StreamHandler\",\n"

" \"level\": \"INFO\",\n"

" \"formatter\": \"simple\",\n"

" \"stream\": \"ext://sys.stdout\",\n"

" \"filters\": [\"warnings_and_below\"]\n"

" },\n"

" \"stderr\": {\n"

" \"class\": \"logging.StreamHandler\",\n"

" \"level\": \"ERROR\",\n"

" \"formatter\": \"simple\",\n"

" \"stream\": \"ext://sys.stderr\"\n"

" },\n"

" \"file\": {\n"

" \"class\": \"logging.FileHandler\",\n"

" \"formatter\": \"simple\",\n"

" \"filename\": \"app.log\",\n"

" \"mode\": \"w\"\n"

" }\n"

" },\n"

" \"root\": {\n"

" \"level\": \"DEBUG\",\n"

" \"handlers\": [\n"

" \"stderr\",\n"

" \"stdout\",\n"

" \"file\"\n"

" ]\n"

" }\n"

"}\n"

"'''\n"

"\n"

"def filter_maker(level):\n"

" level = getattr(logging, level)\n"

"\n"

" def filter(record):\n"

" return record.levelno <= level\n"

"\n"

" return filter\n"

"\n"

"logging.config.dictConfig(json.loads(CONFIG))\n"

"logging.debug('A DEBUG message')\n"

"logging.info('An INFO message')\n"

"logging.warning('A WARNING message')\n"

"logging.error('An ERROR message')\n"

"logging.critical('A CRITICAL message')"

msgstr ""

msgid "And after running it like this:"

msgstr ""

msgid "python main.py 2>stderr.log >stdout.log"

msgstr ""

msgid "We can see the results are as expected:"

msgstr ""

msgid ""

"$ more *.log\n"

"::::::::::::::\n"

"app.log\n"

"::::::::::::::\n"

"DEBUG - A DEBUG message\n"

"INFO - An INFO message\n"

"WARNING - A WARNING message\n"

"ERROR - An ERROR message\n"

"CRITICAL - A CRITICAL message\n"

"::::::::::::::\n"

"stderr.log\n"

"::::::::::::::\n"

"ERROR - An ERROR message\n"

"CRITICAL - A CRITICAL message\n"

"::::::::::::::\n"

"stdout.log\n"

"::::::::::::::\n"

"INFO - An INFO message\n"

"WARNING - A WARNING message"

msgstr ""

msgid "Configuration server example"

msgstr ""

msgid "Here is an example of a module using the logging configuration server::"

msgstr ""

msgid ""

"import logging\n"

"import logging.config\n"

"import time\n"

"import os\n"

"\n"

"# read initial config file\n"

"logging.config.fileConfig('logging.conf')\n"

"\n"

"# create and start listener on port 9999\n"

"t = logging.config.listen(9999)\n"

"t.start()\n"

"\n"

"logger = logging.getLogger('simpleExample')\n"

"\n"

"try:\n"

" # loop through logging calls to see the difference\n"

" # new configurations make, until Ctrl+C is pressed\n"

" while True:\n"

" logger.debug('debug message')\n"

" logger.info('info message')\n"

" logger.warning('warn message')\n"

" logger.error('error message')\n"

" logger.critical('critical message')\n"

" time.sleep(5)\n"

"except KeyboardInterrupt:\n"

" # cleanup\n"

" logging.config.stopListening()\n"

" t.join()"

msgstr ""

msgid ""

"And here is a script that takes a filename and sends that file to the "

"server, properly preceded with the binary-encoded length, as the new logging "

"configuration::"

msgstr ""

msgid ""

"#!/usr/bin/env python\n"

"import socket, sys, struct\n"

"\n"

"with open(sys.argv[1], 'rb') as f:\n"

" data_to_send = f.read()\n"

"\n"

"HOST = 'localhost'\n"

"PORT = 9999\n"

"s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\n"

"print('connecting...')\n"

"s.connect((HOST, PORT))\n"

"print('sending config...')\n"

"s.send(struct.pack('>L', len(data_to_send)))\n"

"s.send(data_to_send)\n"

"s.close()\n"

"print('complete')"

msgstr ""

msgid "Dealing with handlers that block"

msgstr ""

msgid ""

"Sometimes you have to get your logging handlers to do their work without "

"blocking the thread you're logging from. This is common in web applications, "

"though of course it also occurs in other scenarios."

msgstr ""

msgid ""

"A common culprit which demonstrates sluggish behaviour is the :class:"

"`SMTPHandler`: sending emails can take a long time, for a number of reasons "

"outside the developer's control (for example, a poorly performing mail or "

"network infrastructure). But almost any network-based handler can block: "

"Even a :class:`SocketHandler` operation may do a DNS query under the hood "

"which is too slow (and this query can be deep in the socket library code, "

"below the Python layer, and outside your control)."

msgstr ""

msgid ""

"One solution is to use a two-part approach. For the first part, attach only "

"a :class:`QueueHandler` to those loggers which are accessed from performance-"

"critical threads. They simply write to their queue, which can be sized to a "

"large enough capacity or initialized with no upper bound to their size. The "

"write to the queue will typically be accepted quickly, though you will "

"probably need to catch the :exc:`queue.Full` exception as a precaution in "

"your code. If you are a library developer who has performance-critical "

"threads in their code, be sure to document this (together with a suggestion "

"to attach only ``QueueHandlers`` to your loggers) for the benefit of other "

"developers who will use your code."

msgstr ""

msgid ""

"The second part of the solution is :class:`QueueListener`, which has been "

"designed as the counterpart to :class:`QueueHandler`. A :class:"

"`QueueListener` is very simple: it's passed a queue and some handlers, and "

"it fires up an internal thread which listens to its queue for LogRecords "

"sent from ``QueueHandlers`` (or any other source of ``LogRecords``, for that "

"matter). The ``LogRecords`` are removed from the queue and passed to the "

"handlers for processing."

msgstr ""

msgid ""

"The advantage of having a separate :class:`QueueListener` class is that you "

"can use the same instance to service multiple ``QueueHandlers``. This is "

"more resource-friendly than, say, having threaded versions of the existing "

"handler classes, which would eat up one thread per handler for no particular "

"benefit."

msgstr ""

msgid "An example of using these two classes follows (imports omitted)::"

msgstr ""

msgid ""

"que = queue.Queue(-1) # no limit on size\n"

"queue_handler = QueueHandler(que)\n"

"handler = logging.StreamHandler()\n"

"listener = QueueListener(que, handler)\n"

"root = logging.getLogger()\n"

"root.addHandler(queue_handler)\n"

"formatter = logging.Formatter('%(threadName)s: %(message)s')\n"

"handler.setFormatter(formatter)\n"

"listener.start()\n"

"# The log output will display the thread which generated\n"

"# the event (the main thread) rather than the internal\n"

"# thread which monitors the internal queue. This is what\n"

"# you want to happen.\n"

"root.warning('Look out!')\n"

"listener.stop()"

msgstr ""

msgid "which, when run, will produce:"

msgstr ""

msgid "MainThread: Look out!"

msgstr ""

msgid ""

"Although the earlier discussion wasn't specifically talking about async "

"code, but rather about slow logging handlers, it should be noted that when "

"logging from async code, network and even file handlers could lead to "

"problems (blocking the event loop) because some logging is done from :mod:"

"`asyncio` internals. It might be best, if any async code is used in an "

"application, to use the above approach for logging, so that any blocking "

"code runs only in the ``QueueListener`` thread."

msgstr ""

msgid ""

"Prior to Python 3.5, the :class:`QueueListener` always passed every message "

"received from the queue to every handler it was initialized with. (This was "

"because it was assumed that level filtering was all done on the other side, "

"where the queue is filled.) From 3.5 onwards, this behaviour can be changed "

"by passing a keyword argument ``respect_handler_level=True`` to the "

"listener's constructor. When this is done, the listener compares the level "

"of each message with the handler's level, and only passes a message to a "

"handler if it's appropriate to do so."

msgstr ""

msgid "Sending and receiving logging events across a network"

msgstr ""

msgid ""

"Let's say you want to send logging events across a network, and handle them "

"at the receiving end. A simple way of doing this is attaching a :class:"

"`SocketHandler` instance to the root logger at the sending end::"

msgstr ""

msgid ""

"import logging, logging.handlers\n"

"\n"

"rootLogger = logging.getLogger()\n"

"rootLogger.setLevel(logging.DEBUG)\n"

"socketHandler = logging.handlers.SocketHandler('localhost',\n"

" logging.handlers.DEFAULT_TCP_LOGGING_PORT)\n"

"# don't bother with a formatter, since a socket handler sends the event as\n"

"# an unformatted pickle\n"

"rootLogger.addHandler(socketHandler)\n"

"\n"

"# Now, we can log to the root logger, or any other logger. First the "

"root...\n"

"logging.info('Jackdaws love my big sphinx of quartz.')\n"

"\n"

"# Now, define a couple of other loggers which might represent areas in your\n"

"# application:\n"

"\n"

"logger1 = logging.getLogger('myapp.area1')\n"

"logger2 = logging.getLogger('myapp.area2')\n"

"\n"

"logger1.debug('Quick zephyrs blow, vexing daft Jim.')\n"

"logger1.info('How quickly daft jumping zebras vex.')\n"

"logger2.warning('Jail zesty vixen who grabbed pay from quack.')\n"

"logger2.error('The five boxing wizards jump quickly.')"

msgstr ""

msgid ""

"At the receiving end, you can set up a receiver using the :mod:"

"`socketserver` module. Here is a basic working example::"

msgstr ""

msgid ""

"import pickle\n"

"import logging\n"

"import logging.handlers\n"

"import socketserver\n"

"import struct\n"

"\n"

"\n"

"class LogRecordStreamHandler(socketserver.StreamRequestHandler):\n"

" \"\"\"Handler for a streaming logging request.\n"

"\n"

" This basically logs the record using whatever logging policy is\n"

" configured locally.\n"

" \"\"\"\n"

"\n"

" def handle(self):\n"

" \"\"\"\n"

" Handle multiple requests - each expected to be a 4-byte length,\n"

" followed by the LogRecord in pickle format. Logs the record\n"

" according to whatever policy is configured locally.\n"

" \"\"\"\n"

" while True:\n"

" chunk = self.connection.recv(4)\n"

" if len(chunk) < 4:\n"

" break\n"

" slen = struct.unpack('>L', chunk)[0]\n"

" chunk = self.connection.recv(slen)\n"

" while len(chunk) < slen:\n"

" chunk = chunk + self.connection.recv(slen - len(chunk))\n"

" obj = self.unPickle(chunk)\n"

" record = logging.makeLogRecord(obj)\n"

" self.handleLogRecord(record)\n"

"\n"

" def unPickle(self, data):\n"

" return pickle.loads(data)\n"

"\n"

" def handleLogRecord(self, record):\n"

" # if a name is specified, we use the named logger rather than the "

"one\n"

" # implied by the record.\n"

" if self.server.logname is not None:\n"

" name = self.server.logname\n"

" else:\n"

" name = record.name\n"

" logger = logging.getLogger(name)\n"

" # N.B. EVERY record gets logged. This is because Logger.handle\n"

" # is normally called AFTER logger-level filtering. If you want\n"

" # to do filtering, do it at the client end to save wasting\n"

" # cycles and network bandwidth!\n"

" logger.handle(record)\n"

"\n"

"class LogRecordSocketReceiver(socketserver.ThreadingTCPServer):\n"

" \"\"\"\n"

" Simple TCP socket-based logging receiver suitable for testing.\n"

" \"\"\"\n"

"\n"

" allow_reuse_address = True\n"

"\n"

" def __init__(self, host='localhost',\n"

" port=logging.handlers.DEFAULT_TCP_LOGGING_PORT,\n"

" handler=LogRecordStreamHandler):\n"

" socketserver.ThreadingTCPServer.__init__(self, (host, port), "

"handler)\n"

" self.abort = 0\n"

" self.timeout = 1\n"

" self.logname = None\n"

"\n"

" def serve_until_stopped(self):\n"

" import select\n"

" abort = 0\n"

" while not abort:\n"

" rd, wr, ex = select.select([self.socket.fileno()],\n"

" [], [],\n"

" self.timeout)\n"

" if rd:\n"

" self.handle_request()\n"

" abort = self.abort\n"

"\n"

"def main():\n"

" logging.basicConfig(\n"

" format='%(relativeCreated)5d %(name)-15s %(levelname)-8s "

"%(message)s')\n"

" tcpserver = LogRecordSocketReceiver()\n"

" print('About to start TCP server...')\n"

" tcpserver.serve_until_stopped()\n"

"\n"

"if __name__ == '__main__':\n"

" main()"

msgstr ""

msgid ""

"First run the server, and then the client. On the client side, nothing is "

"printed on the console; on the server side, you should see something like:"

msgstr ""

msgid ""

"About to start TCP server...\n"

" 59 root INFO Jackdaws love my big sphinx of quartz.\n"

" 59 myapp.area1 DEBUG Quick zephyrs blow, vexing daft Jim.\n"

" 69 myapp.area1 INFO How quickly daft jumping zebras vex.\n"

" 69 myapp.area2 WARNING Jail zesty vixen who grabbed pay from quack.\n"

" 69 myapp.area2 ERROR The five boxing wizards jump quickly."

msgstr ""

msgid ""

"Note that there are some security issues with pickle in some scenarios. If "

"these affect you, you can use an alternative serialization scheme by "

"overriding the :meth:`~SocketHandler.makePickle` method and implementing "

"your alternative there, as well as adapting the above script to use your "

"alternative serialization."

msgstr ""

msgid "Running a logging socket listener in production"

msgstr ""

msgid ""

"To run a logging listener in production, you may need to use a process-"

"management tool such as `Supervisor <http://supervisord.org/>`_. `Here is a "

"Gist <socket-listener-gist_>`__ which provides the bare-bones files to run "

"the above functionality using Supervisor. It consists of the following files:"

msgstr ""

msgid "File"

msgstr ""

msgid "Purpose"

msgstr ""

msgid ":file:`prepare.sh`"

msgstr ":file:`prepare.sh`"

msgid "A Bash script to prepare the environment for testing"

msgstr ""

msgid ":file:`supervisor.conf`"

msgstr ":file:`supervisor.conf`"

msgid ""

"The Supervisor configuration file, which has entries for the listener and a "

"multi-process web application"

msgstr ""

msgid ":file:`ensure_app.sh`"

msgstr ":file:`ensure_app.sh`"

msgid ""

"A Bash script to ensure that Supervisor is running with the above "

"configuration"

msgstr ""

msgid ":file:`log_listener.py`"

msgstr ":file:`log_listener.py`"

msgid ""

"The socket listener program which receives log events and records them to a "

"file"

msgstr ""

msgid ":file:`main.py`"

msgstr ":file:`main.py`"

msgid ""

"A simple web application which performs logging via a socket connected to "

"the listener"

msgstr ""

msgid ":file:`webapp.json`"

msgstr ":file:`webapp.json`"

msgid "A JSON configuration file for the web application"

msgstr ""

msgid ":file:`client.py`"

msgstr ":file:`client.py`"

msgid "A Python script to exercise the web application"

msgstr ""

msgid ""

"The web application uses `Gunicorn <https://gunicorn.org/>`_, which is a "

"popular web application server that starts multiple worker processes to "

"handle requests. This example setup shows how the workers can write to the "

"same log file without conflicting with one another --- they all go through "

"the socket listener."

msgstr ""

msgid "To test these files, do the following in a POSIX environment:"

msgstr ""

msgid ""

"Download `the Gist <socket-listener-gist_>`__ as a ZIP archive using the :"

"guilabel:`Download ZIP` button."

msgstr ""

msgid "Unzip the above files from the archive into a scratch directory."

msgstr ""

msgid ""

"In the scratch directory, run ``bash prepare.sh`` to get things ready. This "

"creates a :file:`run` subdirectory to contain Supervisor-related and log "

"files, and a :file:`venv` subdirectory to contain a virtual environment into "

"which ``bottle``, ``gunicorn`` and ``supervisor`` are installed."

msgstr ""

msgid ""

"Run ``bash ensure_app.sh`` to ensure that Supervisor is running with the "

"above configuration."

msgstr ""

msgid ""

"Run ``venv/bin/python client.py`` to exercise the web application, which "

"will lead to records being written to the log."

msgstr ""

msgid ""

"Inspect the log files in the :file:`run` subdirectory. You should see the "

"most recent log lines in files matching the pattern :file:`app.log*`. They "

"won't be in any particular order, since they have been handled concurrently "

"by different worker processes in a non-deterministic way."

msgstr ""

msgid ""

"You can shut down the listener and the web application by running ``venv/bin/"

"supervisorctl -c supervisor.conf shutdown``."

msgstr ""

msgid ""