PRTG Manual: Probe Health Sensor
The Probe Health sensor monitors internal PRTG parameters. It shows the status of the probe system. The sensor checks various parameters of the probe system that can affect the quality of the monitoring results.
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
- Dutch: Probe Status
- French: État de la sonde
- German: Zustand der Probe
- Japanese: プローブ正常性
- Portuguese: Funcionamento da sonda
- Russian: Работоспособность зонда
- Simplified Chinese: 探针健康状况
- Spanish: Salud de sonda
- PRTG automatically creates this sensor. You cannot delete it.
- You can only create this sensor on a probe device, either a local probe device or a remote probe device.
- This sensor has a very low performance impact.
- See the Knowledge Base: My probe system is running out of disk space. What can I do?
Click the Settings tab of a sensor to change its settings.
Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created the sensor. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings. See below for details on available settings.
Setting |
Description |
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Sensor Name |
Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.
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Parent Tags |
Shows tags that the sensor inherits from its parent device, parent group, and parent probe. This setting is shown for your information only and cannot be changed here. |
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.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
|
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 ( |
Setting |
Description |
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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.
|
Graph Type |
Define how different channels are shown for this sensor:
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Stack Unit |
This setting is only visible if you enable Stack channels on top of each other as Graph Type. 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. |
By default, all of the following settings are inherited from objects that are higher in the hierarchy. You should 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. You then see the options described below.
For more information, see section Inheritance of Settings.
Click to interrupt the inheritance.
Setting |
Description |
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Scanning Interval |
Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:
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If a Sensor Query Fails |
Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:
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Click to interrupt the inheritance.
Setting |
Description |
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User Group Access |
Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
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Click to interrupt the inheritance.
Setting |
Description |
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Channel Unit Types |
For each type of channel, select the unit in which PRTG displays the data. If you define this setting on probe, group, or device level, these settings can be inherited to all sensors underneath. You can set units for the following channel types (if available):
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Which channels the sensor actually shows might depend on the monitored device, the available components, and the sensor setup.
Channel |
Description |
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CPU Load |
The CPU load in percent that the probe process causes. Extensive CPU load can lead to false, incomplete, and incorrect monitoring results. This value should usually stay below 50%. |
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 in percent. |
Handles |
The counter for the data structures of the operating system. It is responsible for internal resource management. Investigate obviously increasing values that occur repeatedly. |
Health |
The sum of the probe state as a value between 100% (healthy) and 0% (failing). Investigate frequent or repeated health values below 100%.
|
Interval Delay non-WMI&SNMP |
The interval delay in percent for all sensors that are not of the type Simple Network Management Protocol (SNMP) or Windows Management Instrumentation (WMI). If this value is above 0%, try to increase the scanning intervals or distribute your sensors among probes. |
Interval Delay SNMP |
The interval delay in percent for SNMP sensors. If this value is above 0%, there are probably too many SNMP v3 sensors that are very slow. In this case, try to increase the scanning intervals or distribute the sensors among probes. |
Interval Delay WMI |
The interval delay in percent for WMI sensors. If this value is above 0%, WMI sensors were not able to check the target device according to their interval. 100% means that WMI sensors are checked with twice their interval on average. For values above 0%, try to increase the scanning intervals or distribute the sensors among probes to keep the number of WMI sensors per probe below 120 (with a 60-second scanning interval) or 600 (with a 300-second scanning interval). |
Lost Flow Packets |
The number of lost xFlow (NetFlow, jFlow, sFlow, IPFIX) packets in percent. The higher this value, the less xFlow packages PRTG can handle. Usually, this value should be 0%. Investigate increasing values. |
Memory Usage |
The amount of memory that is used by the PRTG probe service as reported by the memory manager. Investigate obviously increasing values that occur repeatedly. If the value is constantly above 2 GB, this indicates that PRTG runs at its limits. In this case, you should distribute some sensors among remote probes. |
Message Queue |
The number of monitoring results that have not been processed by the core yet. This value should usually stay below 1/10 of the sensor count. |
Open Requests |
The number of active monitoring requests. This value should stay below the maximum of 500 open requests. |
Syslog Buffer |
The number of buffered syslog packages. Usually, this value should be 0 (or very low). Investigate increasing values. |
Syslog Drop |
The number of dropped syslog packages |
Threads |
The number of program parts that are running simultaneously. This value can increase with heavy load. Usually, the number should not exceed 100. |
Toplist Memory |
The amount of RAM that the Toplists on this probe are using. Stay below 1 GB memory usage (depending on the available memory on the probe system). If necessary, reduce the number of Toplists or distribute them among probes. |
Trap Buffer |
The number of buffered SNMP traps. Usually, this value should be 0 (or very low). Investigate increasing values. |
KNOWLEDGE BASE
My probe system is running out of disk space. What can I do?
What security features does PRTG include?
For more information about sensor settings, see the following sections: