zulip/zerver/management/commands/check_redis.py

71 lines
2.9 KiB
Python

import logging
import time
from typing import Any, Callable, Optional
from django.conf import settings
from django.core.management.base import BaseCommand, CommandParser, CommandError
from zerver.lib.rate_limiter import RateLimitedUser, \
client, max_api_calls, max_api_window
from zerver.models import get_user_profile_by_id
class Command(BaseCommand):
help = """Checks redis to make sure our rate limiting system hasn't grown a bug
and left redis with a bunch of data
Usage: ./manage.py [--trim] check_redis"""
def add_arguments(self, parser: CommandParser) -> None:
parser.add_argument('-t', '--trim',
dest='trim',
default=False,
action='store_true',
help="Actually trim excess")
def _check_within_range(self, key: str, count_func: Callable[[], int],
trim_func: Optional[Callable[[str, int], None]]=None) -> None:
user_id = int(key.split(':')[1])
user = get_user_profile_by_id(user_id)
entity = RateLimitedUser(user)
max_calls = max_api_calls(entity)
age = int(client.ttl(key))
if age < 0:
logging.error("Found key with age of %s, will never expire: %s" % (age, key,))
count = count_func()
if count > max_calls:
logging.error("Redis health check found key with more elements \
than max_api_calls! (trying to trim) %s %s" % (key, count))
if trim_func is not None:
client.expire(key, max_api_window(entity))
trim_func(key, max_calls)
def handle(self, *args: Any, **options: Any) -> None:
if not settings.RATE_LIMITING:
raise CommandError("This machine is not using redis or rate limiting, aborting")
# Find all keys, and make sure they're all within size constraints
wildcard_list = "ratelimit:*:*:list"
wildcard_zset = "ratelimit:*:*:zset"
trim_func = lambda key, max_calls: client.ltrim(key, 0, max_calls - 1) # type: Optional[Callable[[str, int], None]]
if not options['trim']:
trim_func = None
lists = client.keys(wildcard_list)
for list_name in lists:
self._check_within_range(list_name,
lambda: client.llen(list_name),
trim_func)
zsets = client.keys(wildcard_zset)
for zset in zsets:
now = time.time()
# We can warn on our zset being too large, but we don't know what
# elements to trim. We'd have to go through every list item and take
# the intersection. The best we can do is expire it
self._check_within_range(zset,
lambda: client.zcount(zset, 0, now),
lambda key, max_calls: None)