Features

Added metrics for mobile (5G/LTE/UMTS/GSM) signal strength,
signal quality and mobile access technology in use.
Made Ping check configurable
Added monitoring status chart to the dashboard and a geographic map
which shows a visual representation of the monitoring the status of
the devices.
Added functionality to automatically clear the device's
management_ip when a device goes offline
Added support for specifying the time for received time-series data.
Made read requests to timeseries DB resilient to failures

Changes

Monitoring Template is removed in favour of openwisp monitoring
packages. Follow the migration guide in migrating from
monitoring scripts to monitoring packages section of
openwisp-monitoring documentation.
If you have made changes to the default Monitoring Template, then
create a backup of your template before running migrations. Running
migrations will make changes to the default Monitoring Template.
The time-series database schema for storing interface traffic
and associated WiFi clients has been updated. The data for
interface traffic and associated WiFi clients is stored in
traffic and wifi_clients measurements respectively. The Django
migrations will perform the necessary operations in the time-series
database aysnchronously. It is recommended that you backup the
time-series database before running the migrations.

You can use the migrate_timeseries management command to trigger
the migration of the time-series database.
The interface traffic and associated WiFi clients metrics
store additional tags, i.e. organization_id, location_id and
floorplan_id.

Configuration applied check is triggered whenever the
configuration status of a device changes
Added a default 5 minutes tolerance to CPU and memory alert
settings.
Increased threshold value for disk alert settings from 80% to
90%, since some device models have limited flash and would trigger
the alert in many cases.
Renamed Check.check field to Check.check_type
Made metric health status independent of AlertSetting tolerance.
Added tolerance_crossed parameter in
openwisp_monitoring.monitoring.signals.threshold_crossed signal
The system does not sends connection notifications if the
connectivity of the device changes
Improved UX of device's reachability (ping) chart. Added more
colours to represent different scenarios
Avoid showing charts which have empty data in the REST API response
and in the device charts admin page

Fixed a bug that caused inconsistency in the order of chart summary
values
Fixed bugs in restoring deleted devices using django-reversion
Fixed migrations referencing non-swappable OpenWISP modules that
broke OpenWISP's extensibility
Skip retry for writing metrics beyond retention policy. The celery
worker kept on retrying writing data to InfluxDB even when the data
points crossed the retention policy of InfluxDB. This led to
accumulation of such tasks which overloaded the celery workers.