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>
When we are pulling data from message.display_recipient
for private messages, the user_id field is always
called 'id', not 'user_id', so we can simplify
some defensive code.
This commit was originally automatically generated using `tools/lint
--only=eslint --fix`. It was then modified by tabbott to contain only
changes to a set of files that are unlikely to result in significant
merge conflicts with any open pull request, excluding about 20 files.
His plan is to merge the remaining changes with more precise care,
potentially involving merging parts of conflicting pull requests
before running the `eslint --fix` operation.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This seems like a small change (apart from all the
test changes), but it fundamentally changes how
the app finds "topic" on message objects. Now
all code that used to set "subject" now sets "topic"
on message-like objects. We convert incoming messages
to have topic, and we write to "topic" all the way up
to hitting the server (which now accepts "topic" on
incoming endpoints).
We fall back to subject as needed, but the code will
emit a warning that should be heeded--the "subject"
field is prone to becoming stale for things like
topic changes.
This is part of work to break some of our
nastier circular dependencies in preparation
for our es6 migration.
This commit should facilitate loading leaf-like
modules such as people.js before all of the things
that reload.js depends on.
This makes sure that CSRF token is available while initializing
Socket, irrespective of the order of execution of deferred callbacks
after document becomes ready.
This is part of #9416.
This run_test helper sets up a convention that allows
us to give really short tracebacks for errors, and
eventually we can have more control over running
individual tests. (The latter goal has some
complications, since we often intentionally leak
setup in tests.)
We now isolate the code to transmit messages into transmit.js.
It is stable code that most folks doing UI work in compose.js don't
care about the details of, so it's just clutter there. Also, we may
soon have other widgets than the compose box that send messages.
This change mostly preserves test coverage, although in some cases
we stub at a higher level for the compose path (this is a good thing).
Extracting out transmit.js allows us to lock down 100% coverage on that
file.
Anders Kaseorg
Steve Howell
Rohitt Vashishtha
Shubham Dhama
Tim Abbott