paulmataruso/zulip
1
0
Fork 0
mirror of https://github.com/zulip/zulip.git synced 2025-10-25 09:03:57 +00:00
Code Issues Packages Projects Releases Wiki Activity

deliver_scheduled_*: SELECT FOR UPDATE the relevant rows.

Browse Source 
`deliver_scheduled_emails` and `deliver_scheduled_messages` use their
respective tables like a queue, but do not have guarantees that there
was only one consumer (besides the EMAIL_DELIVERER_DISABLED setting),
and could send duplicate messages if multiple consumers raced in
reading rows.

Use database locking to ensure that the database only feeds a given
ScheduledMessage or ScheduledEmail row to a single consumer.  A second
consumer, if it exists, will block until the first consumer commits
the transaction.
This commit is contained in:
Alex Vandiver
2021-05-17 16:04:03 -07:00
committed by Tim Abbott
parent 82797dd53c
commit 1e67e0f218
2 changed files with 24 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
zerver/management/commands/deliver_scheduled_emails.py
View File

@@ -15,6 +15,7 @@ from typing import Any
from django.conf import settings from django.conf import settings
from django.core.management.base import BaseCommand from django.core.management.base import BaseCommand
from django.db import transaction
from django.utils.timezone import now as timezone_now from django.utils.timezone import now as timezone_now
from zerver.lib.logging_util import log_to_file from zerver.lib.logging_util import log_to_file
@@ -42,17 +43,20 @@ Usage: ./manage.py deliver_scheduled_emails
sleep_forever() sleep_forever()
while True: while True:
email_jobs_to_deliver = ScheduledEmail.objects.filter( found_rows = False
scheduled_timestamp__lte=timezone_now() with transaction.atomic():
) email_jobs_to_deliver = ScheduledEmail.objects.filter(
if email_jobs_to_deliver: scheduled_timestamp__lte=timezone_now()
for job in email_jobs_to_deliver: ).select_for_update()
try: if email_jobs_to_deliver:
deliver_scheduled_emails(job) for job in email_jobs_to_deliver:
except EmailNotDeliveredException: try:
logger.warning("%r not delivered", job) deliver_scheduled_emails(job)
except EmailNotDeliveredException:
logger.warning("%r not delivered", job)
# Less load on the db during times of activity,
# and more responsiveness when the load is low
if found_rows:
time.sleep(10) time.sleep(10)
else: else:
# Less load on the db during times of activity,
# and more responsiveness when the load is low
time.sleep(2) time.sleep(2)

16
zerver/management/commands/deliver_scheduled_messages.py
View File

@@ -5,6 +5,7 @@ from typing import Any
from django.conf import settings from django.conf import settings
from django.core.management.base import BaseCommand from django.core.management.base import BaseCommand
from django.db import transaction
from django.utils.timezone import now as timezone_now from django.utils.timezone import now as timezone_now
from zerver.lib.actions import build_message_send_dict, do_send_messages from zerver.lib.actions import build_message_send_dict, do_send_messages
@@ -65,13 +66,14 @@ Usage: ./manage.py deliver_scheduled_messages
sleep_forever() sleep_forever()
while True: while True:
messages_to_deliver = ScheduledMessage.objects.filter( with transaction.atomic():
scheduled_timestamp__lte=timezone_now(), delivered=False messages_to_deliver = ScheduledMessage.objects.filter(
) scheduled_timestamp__lte=timezone_now(), delivered=False
for message in messages_to_deliver: ).select_for_update()
do_send_messages([self.construct_message(message)]) for message in messages_to_deliver:
message.delivered = True do_send_messages([self.construct_message(message)])
message.save(update_fields=["delivered"]) message.delivered = True
message.save(update_fields=["delivered"])
cur_time = timezone_now() cur_time = timezone_now()
time_next_min = (cur_time + timedelta(minutes=1)).replace(second=0, microsecond=0) time_next_min = (cur_time + timedelta(minutes=1)).replace(second=0, microsecond=0)