That currently tunes the number of MQTT clients employed both for
subscriptions (if shared subscription is used) and for publishing to
a remote broker.
It adds no value: the only mode was `cluster_shareload` and we just as
well can decide to "share" the load across cluster just by looking if
the remote topic is shared subcription filter or not.
Inline `emqx_connector_mqtt_msg` module code into
`emqx_connector_mqtt_worker` module, since it's not really used
anywhere else and does not provide any reusable abstractions.
Fixes https://emqx.atlassian.net/browse/EMQX-10001
Recently, we unified request_timeout in a single field located at the
webhook connector schema. However, the correct fix would be to use
the resource_opts.request_timeout one, as that’s the only one that
allows infinity timeout.
This commit makes sure that the RabbitMQ password filed is marked as
required. This ensures that the user provides a password and that the
bridge does not throw a function clause exception if the password filed
is not set.
Fixes:
https://emqx.atlassian.net/browse/EMQX-9974
connect failure should be at warning level but not error,
the connecting state is visiable from dashbaord
also the resource manager logs connection failures in general
at warning level
This surprisingly simple change yields a big performance improvement
in throughput.
While the previous commit achieves ~ 55 k messages / s
in throughput under some test conditions (100 k concurrent publishers
publishing 1 QoS 1 message per second), the simple change in this
commit improves it further to ~ 63 k messages / s.
Benchmarks indicated that the evaluating one reply function is
consistently quite fast (~ 20 µs), which makes this performance gain
counterintuitive. Perhaps, although each call is cheap, `ehttpc`
calls several of these in a row when there are several sent requests,
and those costs might add up in latency.
This is a performance improvement for webhook bridge.
Since this bridge is called using `async` callback mode, and `ehttpc`
frequently returns errors of the form `normal` and `{shutdown,
normal}` that are retried "for free" by `ehttpc`, we add this behavior
to async requests as well. Other errors are retried too, but they are
not "free": 3 attempts are made at a maximum.
This is important because, when using buffer workers, we should avoid
making them enter the `blocked` state, since that halts all progress
and makes throughput plummet.
Before this change, a separate `manager_id` / `instance_id` was used
as resource manager id, which made connector interface somewhat
inconsistent: part of function calls to connector implementation
used instance id as first argument while the rest used resource id
itself.
Apparently, the async reply returned by ehttpc can be `{shutdown,
normal}` or `{closed, "The connection was lost."}`, in which case the
request should be retried.
```
Apr 28 17:40:41 emqx-0.int.thales bash[48880]: 17:40:41.803 [error] [id: "bridge:webhook:webhook", msg: :unrecoverable_error, reason: {:shutdown, :normal}]
Apr 28 18:36:37 emqx-0.int.thales bash[53368]: 18:36:37.605 [error] [id: "bridge:webhook:webhook", msg: :unrecoverable_error, reason: {:closed, 'The connection was lost.'}]
```
Andrew Mayorov