Since browser clients send messages via websockets and not the API,
this is an important element in making sure mission-critical Zulip
functionality is working.
I'm not altogether happy with this (a better solution would be
database-level locking), but I think it solves the immediate problem
of folks with 2 servers being very likely to run analytics on both of
them.
This results in a brief service interruption (not a graceful restart),
but fixes a bug where on a `supervisorctl restart zulip-django`, we'd
end up leaking a bunch of uwsgi processes.
The mechanism was that sending SIGHUP to uwsgi was a command for it to
gracefully restart, so it'd start doing that (whereas supervisor
expected it to be dying)... and then supervisor would start up the new
uwsgi process group, resulting in 2 uwsgi process groups running.
This, in turn, led to a memory leak that could eventually result in
OOM kills.
The old zulip_ops Nagios configuration depended on Nagios having the
ability to login as the zulip user (with essentially full write
access); this configuration is helpful for limiting nagios to special
"nagios" user with more limited credentials.
Previously, the CRITICAL state would never fire (because x > 6 =>
x > 3). Additionally, 6s is not so unusually high as to deserve being
immediately pageable.
- Add websocket client to create connection with SockJS websocket server.
It contains callback method to launch after connection setup.
- Add '--websocket' parameter to 'check_send_receive_time' script to
check websocket connection.
- Add testing websocket connection to production installation checking.
- Add cronjob to launch websocket connection nagios test.
This makes it possible for Zulip Nagios monitoring to check for
problems impacting the websockets sending code path, which is what all
web users use.
This change adds support for displaying inline open graph previews for
links posted into Zulip.
It is designed to interact correctly with message editing.
This adds the new settings.INLINE_URL_EMBED_PREVIEW setting to control
whether this feature is enabled.
By default, this setting is currently disabled, so that we can burn it
in for a bit before it impacts users more broadly.
Eventually, we may want to make this manageable via a (set of?)
per-realm settings. E.g. I can imagine a realm wanting to be able to
enable/disable it for certain URLs.
(Why is -u needed at all? I’m not sure, but test-run-dev spins forever
“Polling run-dev...” without it.)
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
