History

Anders Kaseorg ea6934c26d 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>		2020-01-14 22:34:00 -08:00
..
architecture-overview.md	dependencies: Remove WebSockets system for sending messages.	2020-01-14 22:34:00 -08:00
changelog.md	version: Update version and changelog for Zulip 2.1.1 release.	2019-12-13 17:19:45 -08:00
contributing.md	…
directory-structure.md	docs: Merge "HTML templates" and "HTML and CSS" docs.	2019-10-16 15:44:26 -07:00
gsoc-ideas.md	docs: Fix typo in gsoc-ideas.md.	2019-10-30 16:20:38 -07:00
index.rst	docs: Move readme-symlink symlink to be just called readme.	2017-11-16 21:43:25 -08:00
readme.md	docs: Move readme-symlink symlink to be just called readme.	2017-11-16 21:43:25 -08:00
roadmap.md	docs: Reduce the number of apparently broken links on github.	2019-10-07 12:08:27 -07:00

readme.md

Zulip overview

Zulip is a powerful, open source group chat application that combines the immediacy of real-time chat with the productivity benefits of threaded conversations. Zulip is used by open source projects, Fortune 500 companies, large standards bodies, and others who need a real-time chat system that allows users to easily process hundreds or thousands of messages a day. With over 500 contributors merging over 500 commits a month, Zulip is also the largest and fastest growing open source group chat project.

Getting started

Click on the appropriate link below. If nothing seems to apply, join us on the Zulip community server and tell us what's up!