Requests aren't throttled properly.

[guyandtheworld]

• I have verified that that issue exists against the master branch of Django REST framework.
• I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• This is not a usage question. (Those should be directed to the discussion group instead.)
• This cannot be dealt with as a third party library. (We prefer new functionality to be in the form of third-party libraries where possible.)
• I have reduced the issue to the simplest possible case.
• I have included a failing test as a pull request. (If you are unable to do so we can still accept the issue.)

I was writing tests for throttling when I found out that throttling doesn't seem to be working properly in development env. None of the requests is getting throttled (anon and user).

This is my REST settings.

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': (
        'rest_framework.pagination.LimitOffsetPagination'),
    'PAGE_SIZE': 10,
    'DEFAULT_PERMISSION_CLASSES': [
        'rest_framework.permissions.IsAuthenticatedOrReadOnly'
    ],
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework_expiring_authtoken.authentication.ExpiringTokenAuthentication',
    ],
    'TEST_REQUEST_DEFAULT_FORMAT': 'json',
    'DEFAULT_THROTTLE_CLASSES': (
        'rest_framework.throttling.AnonRateThrottle',
        'rest_framework.throttling.UserRateThrottle',
        'accounts.throttles.ResendEmailThrottle',
    ),
    'DEFAULT_THROTTLE_RATES': {
        'anon': '100/minute',
        'user': '100/minute',
        'resend_email': '3/hour',
    },
    'DEFAULT_RENDERER_CLASSES': (
        'rest_framework.renderers.JSONRenderer',
    )
}

This is my test code.

class AccountThrottlesTestCase(BaseAPITestCase):

    def setUp(self):
        super(AccountThrottlesTestCase, self).setUp()

    def test_resend_email_throttles(self):
        url = reverse_lazy('accounts:resend_email')
        for i in range(0, 3):
            response = self.client.post(url)
            self.assertEqual(response.status_code, status.HTTP_200_OK)
        response = self.client.post(url)
        self.assertEqual(response.status_code, status.HTTP_429_TOO_MANY_REQUESTS)
Throttles not working.

This is the tests failing by giving 200, whereas it should have been throttled.

FAIL: test_resend_email_throttles (tests.unit.accounts.test_throttles.AccountThrottlesTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/rustbucket/evalai/tests/unit/accounts/test_throttles.py", line 39, in test_resend_email_throttles
    self.assertEqual(response.status_code, status.HTTP_429_TOO_MANY_REQUESTS)
AssertionError: 200 != 429

----------------------------------------------------------------------
Ran 286 tests in 15.994s

Steps to reproduce.

I didn't try reproducing but my best guess was it's something related to DRF because I tried everything else.

Expected Behaviour

Should start throttling after the third request.

Actual Behaviour

Not throttling requests at all. Weird thing I noticed was that when I kept the limit to 0/minute, it suddenly starts throttling the requests.

[xordoquy]

Looks like you are using dummy cache.
I don't think we can do much without further analysis of the issue.