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>
Addresses point 1 of #13533.
MissedMessageEmailAddress objects get tied to the specific that was
missed by the user. A useful benefit of that is that email message sent
to that address will handle topic changes - if the message that was
missed gets its topic changed, the email response will get posted under
the new topic, while in the old model it would get posted under the
old topic, which could potentially be confusing.
Migrating redis data to this new model is a bit tricky, so the migration
code has comments explaining some of the compromises made there, and
test_migrations.py tests handling of the various possible cases that
could arise.
QueueProcessingWorker and LoopQueueProcessingWorker are abstract classes
meant to be subclassed by a class that will define its own consume()
or consume_batch() method. ABCs are suited for that and we can tag
consume/consume_batch with the @abstractmethod wrapper which will
prevent subclasses that don't define these methods properly to be
impossible to even instantiate (as opposed to only crashing once
consume() is called). It's also nicely detected by mypy, which will
throw errors such as this on invalid use:
error: Only concrete class can be given where "Type[TestWorker]" is
expected
error: Cannot instantiate abstract class 'TestWorker' with abstract
attribute 'consume'
Due to it being detected by mypy, we can remove the test
test_worker_noconsume which just tested the old version of this -
raising an exception when the unimplemented consume() gets called. Now
it can be handled already on the linter level.
LoopQueueProcessingWorker can handle exceptions inside consume_batch in
a similar manner to how QueueProcessingWorker handles exceptions inside
consume.
We use the plumbing introduced in a previous commit, to now raise
PushNotificationBouncerRetryLaterError in send_to_push_bouncer in case
of issues with talking to the bouncer server. That's a better way of
dealing with the errors than the previous approach of returning a
"failed" boolean, which generally wasn't checked in the code anyway and
did nothing.
The PushNotificationBouncerRetryLaterError exception will be nicely
handled by queue processors to retry sending again, and due to being a
JsonableError, it will also communicate the error to API users.
We add PushNotificationBouncerRetryLaterError as an exception to signal
an error occurred when trying to communicate with the bouncer and it
should be retried. We use JsonableError as the base class, because this
signal will need to work in two roles:
1. When the push notification was being issued by the queue worker
PushNotificationsWorker, it will signal to the worker to requeue the
event and try again later.
2. The exception will also possibly be raised (this will be added in the
next commit) on codepaths coming from a request to an API endpoint (for
example to add a token, to users/me/apns_device_token). In that case,
it'll be needed to provide a good error to the API user - and basing
this exception on JsonableError will allow that.
This includes adding a new endpoint to the push notification bouncer
interface, and code to call it appropriately after resetting a user's
personal API key.
When we add support for a user having multiple API keys, we may need
to add an additional key here to support removing keys associated with
just one client.
A confirmation object is already created when
do_send_confirmation_email is called just above.
Tweaked by tabbott to remove an unnecessary somewhat hacky database
query.
This should dramatically improve the queue processor's performance in
cases where there's a very high volume of requests on a given endpoint
by a given user, as described in the new docstring.
Until we test this more broadly in production, we won't know if this
is a full solution to the problem, but I think it's likely. We've
never seen the UserActivityInterval worker end up backlogged without a
total queue processor outage, and it should have a similar workload.
Fixes#13180.
We don't actually need to go to the memcached (falling back to the
database) to fetch either user or client objects on every event. For
user objects, we actually can just pass through the user ID
transparently; for client objects, we can use an in-process cache,
since the mapping of string to ID never changes.
Hopefully this does a better job of spurring people to action, and also
suggests a self-service fix if they don't (i.e. contacting the person that
invited them).
zerver/openapi/python_examples.py:105: error: Argument 1 to "get_user_presence" of "Client" has incompatible type "str"; expected "Dict[str, Any]"
zerver/openapi/python_examples.py:563: error: Argument 1 to "add_reaction" of "Client" has incompatible type "Dict[str, object]"; expected "Dict[str, str]"
zerver/openapi/python_examples.py:576: error: Argument 1 to "remove_reaction" of "Client" has incompatible type "Dict[str, object]"; expected "Dict[str, str]"
zerver/worker/queue_processors.py:587: error: Argument "client" to "extract_query_without_mention" has incompatible type "EmbeddedBotHandler"; expected "ExternalBotHandler"
These were only missed because mypy daemon mode requires us to set
`follow_imports = skip` for the `zulip` package.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This feature is intended to cover all of our ways of exporting a
realm, not just the initial "public export" feature, so we should name
things appropriately for that goal.
Additionally, we don't want to include data exports in page_params;
the original implementation was actually buggy and would have.
We were seeing errors when pubishing typical events in the form of
`Dict[str, Any]` as the expected type to be a `Union`. So we instead
change the only non-dictionary call, to pass a dict instead of `str`.
The RealmAuditLog object ID was stored in the event sent to the
deferred_work queue as a means to update the row's extra_data field.
The extra_data field then stores the location of the export.
A unique path was created using the `LOCAL_UPLOADS_DIR` backend, similar
to the code used in `LocalUploadBackend`. The exported tarball was
copied to the directory, and an nginx url was created to serve the file
publicly.
Tweaked by tabbott to output an actual URL.
The upload option will no longer be limited to strictly S3 uploads. This
commit serves as a preliminary step for supporting LOCAL_UPLOADS_DIR as
part of the public only export feature.
An endpoint was created in zerver/views. Basic rate-limiting was
implemented using RealmAuditLog. The idea here is to simply log each
export event as a realm_exported event. The number of events
occurring in the time delta is checked to ensure that the weekly
limit is not exceeded.
The event is published to the 'deferred_work' queue processor to
prevent the export process from being killed after 60s.
Upon completion of the export the realm admin(s) are notified.
Closes#2420
We add rate limiting (max X emails withing Y seconds per realm) to the
email mirror. By creating RateLimitedRealmMirror class, inheriting from
RateLimitedObject, and rate_limit_mirror_by_realm function, following a
mechanism used by rate_limit_user, we're able to have this
implementation mostly rely on the already existing, and proven over
time, rate_limiter.py code. The rules are configurable in settings.py in
RATE_LIMITING_MIRROR_REALM_RULES, analogically to RATE_LIMITING_RULES.
Rate limit verification happens in the MirrorWorker in
queue_processors.py. We don't rate limit missed message emails, as due
to using one time addresses, they're not a spam threat.
test_mirror_worker is adapted to the altered MirrorWorker code and a new
test - test_mirror_worker_rate_limiting is added in test_queue_worker.py
to provide coverage for these changes.
When a bunch of messages with active notifications are all read at
once -- e.g. by the user choosing to mark all messages, or all in a
stream, as read, or just scrolling quickly through a PM conversation
-- there can be a large batch of this information to convey. Doing it
in a single GCM/FCM message is better for server congestion, and for
the device's battery.
The corresponding client-side logic is in zulip/zulip-mobile#3343 .
Existing clients today only understand one message ID at a time; so
accommodate them by sending individual GCM/FCM messages up to an
arbitrary threshold, with the rest only as a batch.
Also add an explicit test for this logic. The existing tests
that happen to cause this function to run don't exercise the
last condition, so without a new test `--coverage` complains.
This adds language paramater to send_future_email. As a result, this
properly internationalizes invitation reminder emails, by passing
correct language into send_future_email.
Fixes#11240.
Apparently, we have a second code path where we might try to call
send_email library functions on old data, namely in the
queue_processors codebase. So we apply the same migration logic here.
This adds a function that sends provided email to all administrators
of a realm, but in a single email. As a result, send_email now takes
arguments to_user_ids and to_emails instead of to_user_id and
to_email.
We adjust other APIs to match, but note that send_future_email does
not yet support the multiple recipients model for good reasons.
Tweaked by tabbott to modify `manage.py deliver_email` to handle
backwards-compatibily for any ScheduledEmail objects already in the
database.
Fixes#10896.
This library was absolutely essential as part of our Python 2->3
migration process, but all of its calls should be either no-ops or
encode/decode operations.
Note also that the library has been wrong since the incorrect
refactoring in 1f9244e060.
Fixes#10807.
While it could make sense to print these logging statements at WARN
level on server startup, it doesn't make sense to do so on every
message (though it perhaps did make sense to do so before more recent
changes added good ways to discover you forgot to configure push
notifications).
Instead, we now just do a WARN log on queue processor startup, and
then at DEBUG level for individual messages.
Fixes#10894.
Previously, MissedMessageWorker used a batching strategy of just
grabbing all the events from the last 2 minutes, and then sending them
off as emails. This suffered from the problem that you had a random
time, between 0s and 120s, to edit your message before it would be
sent out via an email.
Additionally, this made the queue had to monitor, because it was
expected to pile up large numbers of events, even if everything was
fine.
We fix this by batching together the events using a timer; the queue
processor itself just tracks the items, and then a timer-handler
process takes care of ensuring that the emails get sent at least 120s
(and at most 130s) after the first triggering message was sent in Zulip.
This introduces a new unpleasant bug, namely that when we restart a
Zulip server, we can now lose some missed_message email events;
further work is required on this point.
Fixes#6839.
This fixes a couple things:
* process_event() is a pretty vague name
* returning tuples should generally be avoided
* we were producing the same REST parameters in both
subclasses
* relative_url_path was always blank
* request_kwargs was always empty
Now process_event() is called build_bot_request(),
and it only returns request data,
not a tuple of `rest_operation` and `request_data`.
By no longer returning `rest_operation`, there are
fewer moving parts. We just have `do_rest_call` make
a POST call.
Before this change, we instantiated base_url into a superclass
of subclasses that returned base_url into a dictionary that
gets returned to our caller.
Now we just pull base_url out of service when we need to make
the REST call.
This uses the recently introduced active_mobile_push_notification
flag; messages that have had a mobile push notification sent will have
a removal push notification sent as soon as they are marked as read.
Note that this feature is behind a setting,
SEND_REMOVE_PUSH_NOTIFICATIONS, since the notification format is not
supported by the mobile apps yet, and we want to give a grace period
before we start sending notifications that appear as (null) to
clients. But the tracking logic to maintain the set of message IDs
with an active push notification runs unconditionally.
This is designed with at-least-once semantics; so mobile clients need
to handle the possibility that they receive duplicat requests to
remove a push notification.
We reuse the existing missedmessage_mobile_notifications queue
processor for the work, to avoid materially impacting the latency of
marking messages as read.
Fixes#7459, though we'll need to open a follow-up issue for
using these data on iOS.
Private messages are not supported in Slack-format webhook.
Instead of raising a NotImplementedError, we warn the user
that PM service is not supported by sending a message to the
user.
Added tests for the same.
Fixes#9239
Anders Kaseorg
Mateusz Mandera
Tim Abbott
Vishnu KS
Rishi Gupta
Wyatt Hoodes
neiljp (Neil Pilgrim)
Greg Price
Anders Kaseorg
Pragati Agrawal
Raymond Akornor
Steve Howell
Rhea Parekh