Prior to this fix, 'kick' and 'discard' calls may timeout (or
fail for other reason), failures lead to only a log, then
continue to allow the new session to get registered.
As a result, in case a client is stuck, there is no way to
force it to step down, end up with multiple connections (sessions)
for the client ID in dashboard.
After this fix, the stale pids are notified to shutdown
via a gen_server:call, and forced with a exit(Pid, kill) for any
exception happend to the gen_server:call
* refactor(authz): macro move to hrl and rename, add meta example
* refactor(authz_api_mnesia): use config schemas for request validations
* chore(authz_api_mnesia): suite module typerefl fit
* chore(style): authz_api_mnesia style format
feat(stats): track live channel / client count
Track connected client count
In order to correctly display the number of connected clients in our monitor dashboard, we need to track those connections that are actually connected to clients, not considering connections from persistent sessions that are disconnected. Today, the
connections.count that is displayed in the dashboards considers those disconnected persistent sessions as well.
The new statistics can be found in the `emqx_management` plugin, under `/api/v4/stats`, in the keys `live_connections.{max,count}`.
Ported from #6056 .
Track connected client count
In order to correctly display the number of _connected_ clients in our
monitor dashboard, we need to track those connections that are
actually connected to clients, not considering connections from
persistent sessions that are disconnected. Today, the
`connections.count` that is displayed in the dashboards considers
those disconnected persistent sessions as well.
The new statistics can be found in the
[`emqx_management`](https://github.com/emqx/emqx/tree/main-v4.4/apps/emqx_management)
plugin, under `/api/v4/stats`, in the keys
`live_connections.{max,count}`.
A few FVT tests are very flaky when run in rlog core+replicant cluster
configuration (for instance `V5/test_publish.py::test_topic`). We are
disabling this test configuration temporarily while we investigate
further and mitigate it.
