Multiple TimedRotatingFileHandler with similar names but different backup counts do not work

[ilCatania]

Bug report

When setting up multiple logging handlers of type TimedRotatingFileHandler that log to the same directory and only differ by the file extension, rollover does not work properly for either of them.

Consider this configuration:

root = logging.getLogger()
root.addHandler(TimedRotatingFileHandler("test.log", when="S", backupCount=2, delay=True))
root.addHandler(TimedRotatingFileHandler("test.log.json", when="S", backupCount=1, delay=True))

running this for several seconds should cause the logging directory to have 5 files (time stamps would obviously vary based on when you run it) :

test.log
test.log.2022-05-25_05-19-19
test.log.2022-05-25_05-19-18
test.log.json
test.log.json.2022-05-25_05-19-19

However, the second handler deletes files that should only match the first handler, so it ends up not deleting its own files:

test.log
test.log.2022-05-25_05-19-19
test.log.json
test.log.json.2022-05-25_05-19-17
test.log.json.2022-05-25_05-19-18
test.log.json.2022-05-25_05-19-19

Digging through code this seems to be caused by the change in bpo-44753 aka #88916, reverting this change solves the issue for me.

Here's the full code to reproduce the issue:

import logging
import datetime
from logging.handlers import TimedRotatingFileHandler
from tempfile import TemporaryDirectory
from pathlib import Path
from time import sleep

with TemporaryDirectory() as td:
    tmp_path = Path(td)
    filename = "test.log"
    filename_json = f"{filename}.json"
    logfile = tmp_path / filename
    logfile_json = tmp_path / filename_json

    h1 = TimedRotatingFileHandler(logfile, when="S", backupCount=2, delay=True)
    h2 = TimedRotatingFileHandler(logfile_json, when="S", backupCount=1, delay=True)
    times = []
    for log_str in ("hi1", "hi2", "hi3", "hi4"):
        times.append(datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S"))
        for h in (h1, h2):
            h.emit(logging.LogRecord("name", logging.INFO, "path", 1, log_str, (), None))
        sleep(1)
    assert logfile.is_file()
    actual = set(f.name for f in tmp_path.iterdir())
    expected = {
        "test.log",
        f"test.log.{times[-3]}",
        f"test.log.{times[-2]}",
        "test.log.json",
        f"test.log.json.{times[-2]}",
    }
    assert actual == expected, (
        f"\n\texpected:\t{','.join(expected)}" f"\n\tactual:\t\t{','.join(actual)}"
    )
    assert logfile.read_text() == "hi4\n"
    assert logfile_json.read_text() == "hi4\n"
    assert (tmp_path / f"{filename}.{times[-3]}").read_text() == "hi2\n"
    assert (tmp_path / f"{filename_json}.{times[-2]}").read_text() == "hi3\n"

Your environment

Tested this with Python 3.9.7 and 3.10.4, and with the current development cpython code.

Linux 3.10.0-957.27.2.el7.x86_64 #1 SMP Mon Jul 29 17:46:05 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Linked PRs

• gh-93205: When rotating logs with no namer specified, match whole extension #93224
• [3.12] gh-93205: When rotating logs with no namer specified, match whole extension (GH-93224) #115784
• [3.11] gh-93205: When rotating logs with no namer specified, match whole extension (GH-93224) #115785

[ilCatania]

Please note that a similar test case using just RotatingFileHandler works perfectly fine too.

[ilCatania]

Code has changed a bit since python 3.10 due to bpo-46063 (GH-90221) so i'll try to submit a test