The MQTT Round Trip sensor monitors the availability of a Message Queue Telemetry Transport (MQTT) broker (server), connects to the broker as a publishing and subscribing client, and sends the data packets using a predefined topic.
MQTT Round Trip Sensor
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
This sensor was converted to a new framework. MQTT Round Trip sensors that were added before PRTG 20.2.59 do not work anymore. We recommend that you pause existing sensors to keep their historic data. To continue monitoring, please add a new MQTT Round Trip sensor.
This sensor uses lookups to determine the status values of one or more channels.
If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?
This setting is for your information only. You cannot change it.
Tags
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).
For performance reasons, it can take some minutes until you can filter for new tags that you added.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
roundtrip
mqttroundtrip
Priority
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority () to the highest priority ().
MQTT Specific
MQTT Specific
Setting
Description
Topic
Enter the topic for the round trip. The default is PRTG/roundtrip/%sensorid.
PRTG replaces %sensorid with the sensor's ID.
Connection Settings
Define the connection settings for the connection to the MQTT broker:
Use default settings: Use the default connection settings.
Use custom settings: Use a ClientID that you can specify below.
ClientID
This setting is only visible if you select Use custom settings above.
Enter the ClientID for the connection to the MQTT broker. The default is PRTG_%sensorid.
PRTG replaces %sensorid with the sensor's ID. For the subscribing client, PRTG automatically adds _subscriber to the ClientID. For the publishing client, PRTG automatically adds _publisher to the ClientID.
Sensor Display
Sensor Display
Setting
Description
Primary Channel
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.
Graph Type
Define how different channels are shown for this sensor:
Show channels independently (default): Show a graph for each channel.
Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic. You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).
Stack Unit
This setting is only visible if you select Stack channels on top of each other above.
Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.
Debug Options
Debug Options
Setting
Description
Result Handling
Define what PRTG does with the sensor result:
Discard result: Do not store the sensor result.
Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file name is Result of Sensor [ID].log. This setting is for debugging purposes. PRTG overwrites this file with each scanning interval.
This option is not available when the sensor runs on the hosted probe of a PRTG Hosted Monitor instance.
In a cluster, PRTG stores the result in the PRTG data directory of the master node.
Inherited Settings
By default, all of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance and to display its options.
For more information, see section Root Group Settings, section Scanning Interval.
Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Schedules, Dependencies, and Maintenance Window
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
Access Rights
Access Rights
For more information, see section Root Group Settings, section Access Rights.
Channel Unit Configuration
Which channel units are available depends on the sensor type and the available parameters. If no configurable channels are available, this field shows No configurable channels.
Channel Unit Configuration
For more information, see section Root Group Settings, section Channel Unit Configuration.
Channel List
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel
Description
Downtime
In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status
Publisher Connection Time
The time it takes the publisher to connect
Round Trip Time
The RTT of the message (after both publisher and subscriber connect)
This channel is the primary channel by default.
Status
The round trip status
Up status: Roundtrip Complete
Down status: Message Not Received, Message Not Sent, Publisher Could Not Connect, Subscriber Could Not Connect