Fixes https://emqx.atlassian.net/browse/EMQX-10773
- Makes the timeout for probing a bridge more malleable to account for differences between
each database.
- Increases GCP PubSub Consumer default health check timeout to account for GCP
slowness/throttling.
MongoDB connector currently does not support batching
so the batch_size option has no effect.
However we cannot remove the field, so we choose to hide it from
schema
See:
https://emqx.atlassian.net/wiki/spaces/P/pages/612368639/open+e5.1+remove+auto+restart+interval+from+buffer+worker+resource+options
Current problem:
In 5.0.x, we have two timer options that control the state changing of buffer worker
resources: auto_restart_interval and health_check_interval.
- auto_restart_interval controls how often the resource attempts to transition from
disconnected to connected.
- health_check_interval controls how often the resource is checked and potentially moved
from connected to disconnected or connecting.
The existence of two independent timers for very similar purposes is confusing to users,
QA and even developers. Also, an intimately related configuration is request_timeout,
which can interact badly with auto_restart_interval if the latter is poorly configured:
requests may always expire if request_timeout < auto_restart_interval and if the resource
enters the disconnected state. For health_check_interval, we attempt to derive a sane
default that gives requests a chance to retry (if request timeout is finite, then the
resource retries requests with a period of min(health_check_interval, request_timeout /
3).
Another problem with the separate auto_restart_interval is that its default value (60 s)
is too high when compared to the default request timeout and health check, leading to the
problems described above if not tuned.
Proposed solution:
We propose to drop auto_restart_interval in favor of health_check_interval, which will be
used for both disconnected -> connected and connected -> {disconnected, connecting}
transition checks. With that, the resource will attempt to reconnect at the same interval
as the health check, which currently is 15 s.
Also, as two smaller changes to accompany this one:
- Increase the default request_timeout from 15 s to 45 s.
- Rename request_timeout to request_ttl.
Fixes https://emqx.atlassian.net/browse/EMQX-9905
Since calling `telemetry` is costly in a hot path, we instead collect
metrics inside the buffer workers state and periodically flush them,
rather than immediately as events happen.
Fixes https://emqx.atlassian.net/browse/EMQX-9864
Setting a very large interval can cause `erlang:start_timer` to crash.
Also, setting auto_restart_interval or health_check_interval to "0s"
causes the state machine to be in loop as time 0 is handled separately:
| state_timeout() = timeout() | integer()
| (...)
| If Time is relative and 0 no timer is actually started, instead the the
| time-out event is enqueued to ensure that it gets processed before any
| not yet received external event.
from "https://www.erlang.org/doc/man/gen_statem.html#type-state_timeout"
Therefore, both fields are now validated against the range [1ms, 1h],
which doesn't cause above issues.
Fixes https://emqx.atlassian.net/browse/EMQX-9367
For better user experience and performance for the average bridge, we
should change the default queue mode to `memory_only`, as was the
behavior of most bridges in e4.x. This leads to better performance
when message rate is high enough and the remote resource is not
keeping up with EMQX.
Also, we set the default segment size to equal max queue bytes.
Port of https://github.com/emqx/emqx/pull/10154 for `release-50`
Fixes https://emqx.atlassian.net/browse/EMQX-9099
Originally, the `resume_interval`, which is what defines how often a
buffer worker will attempt to retry its inflight window, was set to
the same as the `health_check_interval`. This had the problem that,
with default values, `health_check_interval = request_timeout`. This
meant that, if a buffer worker with those configs were ever blocked,
all requests would have timed out by the time it retried them.
Here we change the default `resume_interval` to a reasonable value
dependent on `health_check_interval` and `request_timeout`, and also
expose that as a hidden parameter for fine tuning if necessary.
Fixes https://emqx.atlassian.net/browse/EMQX-9130
Since buffer workers always support async calls ("outer calls"), we
should decouple those two call modes (inner and outer), and avoid
exposing the inner call configuration to user to avoid complexity.
For bridges that currently only allow sync query modes, we should
allow them to be configured with async. That means basically all
bridge types except Kafka Producer.
Also removes the previously added alarm for request timeout.
There are situations where having a short request timeout and a long
health check interval make sense, so we don't want to alarm the user
for those situations. Instead, we automatically attempt to set a
reasonable `resume_interval` value.
This commit makes sure the inflight window setting is present for the
clickhouse bridge. It also changes emqx_resource_schema that previously
removed the inflight window setting from resources with query mode
`always_sync`. We don't need to do that because all bridges that uses
the buffer worker queue will get async call handling even if the bridge
don't support the async callback.
Co-authored-by: Zaiming (Stone) Shi <zmstone@gmail.com>
This makes the buffer/resource workers always use `replayq` for
queuing, along with collecting multiple requests in a single call.
This is done to avoid long message queues for the buffer workers and
rely on `replayq`'s capabilities of offloading to disk and detecting
overflow.
Also, this deprecates the `enable_batch` and `enable_queue` resource
creation options, as: i) queuing is now always enables; ii) batch_size
> 1 <=> batch_enabled. The corresponding metric
`dropped.queue_not_enabled` is dropped, along with `batching`. The
batching is too ephemeral, especially considering a default batch time
of 20 ms, and is not shown in the dashboard, so it was removed.
