The `no_proxy` parameter does not work to remove proxying[1]; in this
case, since all requests with this adapter are to the internal Tornado
process, explicitly pass in an empty set of proxies to disable
proxying.
[1] https://github.com/psf/requests/issues/4600
Having both of these is confusing; TORNADO_SERVER is used only when
there is one TORNADO_PORT. Its primary use is actually to be _unset_,
and signal that in-process handling is to be done.
Rename to USING_TORNADO, to parallel the existing USING_RABBITMQ, and
switch the places that used it for its contents to using
TORNADO_PORTS.
While urllib3 retries all connection errors, it only retries a subset
of read errors, since not all requests are safe to retry if they are
not idempotent, and the far side may have already processed them once.
By default, the only methods that are urllib3 retries read errors on
are GET, TRACE, DELETE, OPTIONS, HEAD, and PUT. However, all of the
requests into Tornado from Django are POST requests, which limits the
effectiveness of bb754e0902.
POST requests to `/api/v1/events/internal` are safe to retry; at worst,
they will result in another event queue, which is low cost and will be
GC'd in short order.
POST requests to `/notify_tornado` are _not_ safe to retry, but this
codepath is only used if USING_RABBITMQ is False, which only occurs
during testing.
Enable retries for read errors during all POSTs to Tornado, to better
handle Tornado restarts without 500's.
Without an explicit port number, the `stdout_logfile` values for each
port are identical. Supervisor apparently decides that it will
de-conflict this by appending an arbitrary number to the end:
```
/var/log/zulip/tornado.log
/var/log/zulip/tornado.log.1
/var/log/zulip/tornado.log.10
/var/log/zulip/tornado.log.2
/var/log/zulip/tornado.log.3
/var/log/zulip/tornado.log.7
/var/log/zulip/tornado.log.8
/var/log/zulip/tornado.log.9
```
This is quite confusing, since most other files in `/var/log/zulip/`
use `.1` to mean logrotate was used. Also note that these are not all
sequential -- 4, 5, and 6 are mysteriously missing, though they were
used in previous restarts. This can make it extremely hard to debug
logs from a particular Tornado shard.
Give the logfiles a consistent name, and set them up to logrotate.
By defaults, `requests` has no timeout on requests, which can lead to
waiting indefinitely. Add a half-second timeout on these; this is
applied _inside_ each retry, not overall -- that is, with retries any
of these functions may take a total of 1.5s.
Use the `no_proxy` proxy, which explicitly disables proxy usage for
particular hosts. This is a slightly cleaner solution than ignoring
all of the environment, as removing proxies is specifically what we
are attempting to accomplish.
The change in #2764 provided a better error message on one of the
three calls into Tornado, but left the other two with the old error
message. `raise_for_status` was used on two out of three.
Use a custom HTTPAdapter to apply this pattern to all requests from
Django to Tornado.
Anders Kaseorg
Alex Vandiver
Tim Abbott