How to throttle Django error emails

Question

I use django error reporting via email. It is normally a very helpful feature, except that now we have 5 minutes of database downtime and I got 2000 emails. Is there any middleware that will help me throttle the number of emails django can send out per minute?

Answer 1

Using Gattster's great answer as an example, I wrote a simple implementation based on django's built-in cache functions.

# -*- coding: utf-8 -*-

from django.utils.log import AdminEmailHandler
from django.core.cache import cache


class ThrottledAdminEmailHandler(AdminEmailHandler):

    PERIOD_LENGTH_IN_SECONDS = 10
    MAX_EMAILS_IN_PERIOD = 1
    COUNTER_CACHE_KEY = "email_admins_counter"

    def increment_counter(self):
        try:
            cache.incr(self.COUNTER_CACHE_KEY)
        except ValueError:
            cache.set(self.COUNTER_CACHE_KEY, 1, self.PERIOD_LENGTH_IN_SECONDS)
        return cache.get(self.COUNTER_CACHE_KEY)

    def emit(self, record):
        try:
            counter = self.increment_counter()
        except Exception:
            pass
        else:
            if counter > self.MAX_EMAILS_IN_PERIOD:
                return
        super(ThrottledAdminEmailHandler, self).emit(record)

And the logging configuration has been changed in Django 1.9 as well, so in order for this handler to work, you need to configure logging as:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': True,
    'handlers': {
        'mail_admins': {
            'level': 'ERROR',
            'class': 'fully.qualified.path.to.handler.ThrottledAdminEmailHandler'
        }
    },
    'loggers': {
        'django': {
            'handlers': ['mail_admins'],
            'level': 'ERROR',
            'propagate': True,
        },
    }
}

where the change is only to change the name of the logger from django.request to django. If you look in the logging system documentation, this could probably be achieved in a cleaner (?) way by implementing a logging filter.