This low-level interface allows consuming from a queue with timeouts.
This can be used to either consume in batches (with an upper timeout),
or one-at-a-time. This is notably more performant than calling
`.get()` repeatedly (what json_drain_queue does under the hood), which
is "*highly discouraged* as it is *very inefficient*"[1].
Before this change:
```
$ ./manage.py queue_rate --count 10000 --batch
Purging queue...
Enqueue rate: 11158 / sec
Dequeue rate: 3075 / sec
```
After:
```
$ ./manage.py queue_rate --count 10000 --batch
Purging queue...
Enqueue rate: 11511 / sec
Dequeue rate: 19938 / sec
```
[1] https://www.rabbitmq.com/consumers.html#fetching
Despite its name, the `queue_size` method does not return the number
of items in the queue; it returns the number of items that the local
consumer has delivered but unprocessed. These are often, but not
always, the same.
RabbitMQ's queues maintain the queue of unacknowledged messages; when
a consumer connects, it sends to the consumer some number of messages
to handle, known as the "prefetch." This is a performance
optimization, to ensure the consumer code does not need to wait for a
network round-trip before having new data to consume.
The default prefetch is 0, which means that RabbitMQ immediately dumps
all outstanding messages to the consumer, which slowly processes and
acknowledges them. If a second consumer were to connect to the same
queue, they would receive no messages to process, as the first
consumer has already been allocated them. If the first consumer
disconnects or crashes, all prior events sent to it are then made
available for other consumers on the queue.
The consumer does not know the total size of the queue -- merely how
many messages it has been handed.
No change is made to the prefetch here; however, future changes may
wish to limit the prefetch, either for memory-saving, or to allow
multiple consumers to work the same queue.
Rename the method to make clear that it only contains information
about the local queue in the consumer, not the full RabbitMQ queue.
Also include the waiting message count, which is used by the
`consume()` iterator for similar purpose to the pending events list.
We modify access_stream_for_delete_or_update function to return
Subscription object also along with stream. This change will be
helpful in avoiding an extra query to get subscription object in
code for updating subscription role.
For streams in which only full members are allowed to post,
we block guest users from posting there.
Guests users were blocked from posting to admin only streams
already. So now, guest users can only post to
STREAM_POST_POLICY_EVERYONE streams.
This is not a new feature but a bugfix which should have
happened when implementing full member stream policy / guest users.
Replaced ImageOps.fit by ImageOps.pad, in zerver/lib/upload.py, which
returns a sized and padded version of the image, expanded to fill the
requested aspect ratio and size.
Fixes part of #16370.
Currently, drain_queue and json_drain_queue ack every message as it is
pulled off of the queue, until the queue is empty. This means that if
the consumer crashes between pulling a batch of messages off the
queue, and actually processing them, those messages will be
permanently lost. Sending an ACK on every message also results in a
significant amount lot of traffic to rabbitmq, with notable
performance implications.
Send a singular ACK after the processing has completed, by making
`drain_queue` into a contextmanager. Additionally, use the `multiple`
flag to ACK all of the messages at once -- or explicitly NACK the
messages if processing failed. Sending a NACK will re-queue them at
the front of the queue.
Performance of a no-op dequeue before this change:
```
$ ./manage.py queue_rate --count 50000 --batch
Purging queue...
Enqueue rate: 10847 / sec
Dequeue rate: 2479 / sec
```
Performance of a no-op dequeue after this change (a 25% increase):
```
$ ./manage.py queue_rate --count 50000 --batch
Purging queue...
Enqueue rate: 10752 / sec
Dequeue rate: 3079 / sec
```
Part of #16094.
Moved the language selection preference logic from home.py to a new
function in i18n.py to avoid repetition in analytics views and home
views.
This prevents the memcached connection from being shared across
multiple processes, and hopefully addresses unexpected behavior from
cached functions like get_user_profile_by_id invoked inside the worker
processes.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
We call build_message_send_dict from check_message instead of
do_send_messages.
This is a prep commit for adding a new setting for handling
wildcard mentions in large streams.
We extract the loop for building message dict in
do_send_messages in a separate function named
build_message_send_dict.
This is a prep commit for moving the code for building
of message dict in check_message.
There is a bug where we send event for even
those messages which do not have embedded links
as we are using single set 'links_for_embed' to
check whether we have to send event for
embedded links or not.
This commit fixes the bug by adding 'links_for_embed'
in message dict itself and send the event only
if that message has embedded links.
This commit removes the unnecessary comment which was added in
9454683108, when we were using message.get() for keys which
were also passed as args in do_send_messages, but there are no
such keys in the current code.
This commit removes the unnecessary line of code to get
rendered_content from message dict sent by check_message
when it actually does not inlcude 'rendered_content' key.
This line was added in 9454683108, but now we do not send
rendered_content in the message dict as we render the message
in do_send_messages itself.
A later commit alters `authenticate` of EmailAuthBackend to
add a store `needs_to_change_password` variable to session
which is useful to insist users on changing their weak password.
The tests start failing with that change because client.login()
runs `authenticate` without a `request` object. So, this commit
sends a request object with `request.session=self.client.session`
to self.client.login() in tests wherever needed.
We now no longer define any schemas in test_events--all
of them are in event_schema, which helps our tooling
cross-check schemas for openapi and node tests.
It happens that whether you add a reaction or remove
a reaction, we send the exact same fields, just using
a different op code.
This sort of symmetry is actually kind of rare, as
usually "add" events have more fields, and "remove" events
might just send an id of something to remove.
Our openapi schema treats these as two seperate events,
so we are more consistent with it, and it helps our
schema-checking tooling for node fixtures, too.
Note that we now have to exempt the two events from
our openapi checks, due to the is_mirror_dummy field
in the deprecated user block. We can decide how to
handle this later--one possibility is to just add it
as an optional field on the event_schema side.
Note that we use value_type for value instead of
bool, since properties can be non-bool things
like color, which we just don't test now. We
should test them.
We more than compensate for this by checking
the actual value of the value in
check_subscription_update.
Alex Vandiver
sahil839
Aman Agrawal
Anders Kaseorg
akshatdalton
Abhijeet Prasad Bodas
Tim Abbott
Steve Howell
Vishnu KS
palash
Dinesh
Clara Dantas