zulip/zerver/management/commands/purge_queue.py

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from argparse import ArgumentParser
from typing import Any
from django.core.management import CommandError
from django.core.management.base import BaseCommand
from zerver.lib.queue import SimpleQueueClient
from zerver.worker.queue_processors import get_active_worker_queues
class Command(BaseCommand):
def add_arguments(self, parser: ArgumentParser) -> None:
parser.add_argument(dest="queue_name", nargs='?',
help="queue to purge")
parser.add_argument('--all', action="store_true",
help="purge all queues")
help = "Discards all messages from the given queue"
def handle(self, *args: Any, **options: str) -> None:
def purge_queue(queue_name: str) -> None:
queue = SimpleQueueClient()
queue.ensure_queue(queue_name, lambda channel: channel.queue_purge(queue_name))
if options['all']:
for queue_name in get_active_worker_queues():
purge_queue(queue_name)
print("All queues purged")
elif not options['queue_name']:
raise CommandError("Missing queue_name argument!")
else:
queue_name = options['queue_name']
if not (queue_name in get_active_worker_queues() or
dependencies: Remove WebSockets system for sending messages. Zulip has had a small use of WebSockets (specifically, for the code path of sending messages, via the webapp only) since ~2013. We originally added this use of WebSockets in the hope that the latency benefits of doing so would allow us to avoid implementing a markdown local echo; they were not. Further, HTTP/2 may have eliminated the latency difference we hoped to exploit by using WebSockets in any case. While we’d originally imagined using WebSockets for other endpoints, there was never a good justification for moving more components to the WebSockets system. This WebSockets code path had a lot of downsides/complexity, including: * The messy hack involving constructing an emulated request object to hook into doing Django requests. * The `message_senders` queue processor system, which increases RAM needs and must be provisioned independently from the rest of the server). * A duplicate check_send_receive_time Nagios test specific to WebSockets. * The requirement for users to have their firewalls/NATs allow WebSocket connections, and a setting to disable them for networks where WebSockets don’t work. * Dependencies on the SockJS family of libraries, which has at times been poorly maintained, and periodically throws random JavaScript exceptions in our production environments without a deep enough traceback to effectively investigate. * A total of about 1600 lines of our code related to the feature. * Increased load on the Tornado system, especially around a Zulip server restart, and especially for large installations like zulipchat.com, resulting in extra delay before messages can be sent again. As detailed in https://github.com/zulip/zulip/pull/12862#issuecomment-536152397, it appears that removing WebSockets moderately increases the time it takes for the `send_message` API query to return from the server, but does not significantly change the time between when a message is sent and when it is received by clients. We don’t understand the reason for that change (suggesting the possibility of a measurement error), and even if it is a real change, we consider that potential small latency regression to be acceptable. If we later want WebSockets, we’ll likely want to just use Django Channels. Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
2019-07-23 01:43:40 +02:00
queue_name.startswith("notify_tornado")):
raise CommandError(f"Unknown queue {queue_name}")
print(f"Purging queue {queue_name}")
purge_queue(queue_name)
print("Done")