Managing Multiple Chromologger Instances in One App

Chromologger allows any number of Logger instances to be active at the same time, each writing independently to its own file. This lets you separate concerns cleanly: access events, application errors, and performance metrics each live in their own log file and can be inspected, archived, or rotated individually.

Creating multiple loggers

multiple_loggers.py

from chromologger import Logger
import os

os.makedirs('./logs', exist_ok=True)

access_logger = Logger('./logs/access.log')
error_logger  = Logger('./logs/errors.log')
perf_logger   = Logger('./logs/performance.log')

Each constructor call opens a separate file handle in append mode, so existing log entries are preserved across restarts.

Using them independently

Route each event to the logger that matches its purpose:

access_logger.log('GET /api/users - 200')
perf_logger.log('DB query completed in 12ms')

try:
    process_request()
except Exception as e:
    error_logger.log_e(e)

Calls to different loggers are completely independent — writing to access_logger has no effect on error_logger or perf_logger.

Closing all loggers

Collect your loggers in a list so you can close them all in a single loop, typically inside a finally block:

loggers = [access_logger, error_logger, perf_logger]
for lg in loggers:
    lg.close()

close() returns True for each logger that had a valid file open and False otherwise, so you can check the return values if you need to confirm cleanup.

Web application example

The pattern below shows how multiple loggers integrate naturally into an application class:

web_app.py

from chromologger import Logger
from datetime import datetime
import os

log_dir = './logs'
os.makedirs(log_dir, exist_ok=True)

access_logger = Logger(f'{log_dir}/access.log')
error_logger  = Logger(f'{log_dir}/errors.log')

class WebApp:
    def handle_request(self, user_id: str, endpoint: str):
        try:
            access_logger.log(f'User {user_id} → {endpoint}')
            # ... request handling ...
            access_logger.log(f'Request OK for {user_id}')
        except Exception as e:
            error_logger.log_e(e)

    def shutdown(self):
        for lg in [access_logger, error_logger]:
            lg.close()

Each Logger opens its file in append mode. Concurrent writes from multiple threads to the same file are not guaranteed to be safe — file writes may interleave and produce corrupted log lines. Use a separate log file per Logger instance (as shown above) rather than pointing multiple loggers at the same path.

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Troubleshooting

Managing Multiple Chromologger Instances in One App

Creating multiple loggers

Using them independently

Closing all loggers

Web application example

​Creating multiple loggers

​Using them independently

​Closing all loggers

​Web application example

Creating multiple loggers

Using them independently

Closing all loggers

Web application example