Health Monitoring
The health of a thin-edge.io service or any other service
that is running on the thin-edge.io device
or on the child
device can be monitored from the Cumulocity IoT by sending the health-status
message to Cumulocity IoT.
Publish health status​
A health status message can be published for any service on a status/health
channel. The health message should at least contain the status
of the service.
The status
here can be up
or down
or any other string. For example, unknown
.
For example, to update the health status of device/my-device/service/my-test-service
service, one has to send the
following message:
- tedge
- mosquitto
- mqtt
tedge mqtt pub -r -q 2 'te/device/my-device/service/my-test-service/status/health' '{
"status": "up"
}'
mosquitto_pub -r -q 2 -t 'te/device/my-device/service/my-test-service/status/health' -m '{
"status": "up"
}'
te/device/my-device/service/my-test-service/status/health
{
"status": "up"
}
The health status message has to be sent as a retain message.
When an empty health status message is sent, e.g. {}
or ''
, the status
will be replaced with unknown
.
Conversion of the health status message to Cumulocity IoT service monitor message​
The tedge-mapper-c8y
will translate any health status message that is received on te/+/+/+/+/status/health
topic to
Cumulocity Service creation SmartREST message and
send it to the Cumulocity
cloud. If a service was not previously registered and it fulfills the requirements for
auto-registration, it will be auto-registered as described in the Auto Registration
section.
For example, assuming a service device/child1/service/service1
, running on a device device/child1//
, which is a
child device of thin-edge.io device device/main//
with an ID of TE_DEVICE
, the resulting topic mapping looks like
this:
thin-edge.io health status message
- tedge
- mosquitto
- mqtt
tedge mqtt pub -r -q 2 'te/device/child1/service/service1/status/health' '{
"status": "up"
}'
mosquitto_pub -r -q 2 -t 'te/device/child1/service/service1/status/health' -m '{
"status": "up"
}'
te/device/child1/service/service1/status/health
{
"status": "up"
}
Cumulocity IoT (output)
c8y/s/us/<device-id>:device:child1
102,<device-id>:device:child1:service:service1,service,service1,up
Configuring the default service type​
The default service type can be configured using the tedge
cli.
The example below shows how one can set the default service type to systemd
.
sudo tedge config set service.type systemd
When the type
property was not included in the service registration message, then the configured default value
will be used by the mapper while auto-registering the service.
To clear the configured default service type one can use the command below.
This will set the service.type
to service
.
sudo tedge config unset service.type
References
More info about the service monitoring can be found in the link below.