<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: Probe Health Sensor

The Probe Health sensor monitors internal PRTG parameters. It shows the status of the probe system and checks various parameters of the probe system that can affect the quality of the monitoring results.

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

Probe Health Sensor

Probe Health Sensor

Sensor in Other Languages

  • 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

Remarks

  • 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?

Basic Sensor Settings

Click the Settings tab of a sensor to change its settings.

Basic Sensor Settings

Basic Sensor Settings

Setting

Description

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.

i_round_blueIf 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?

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

i_round_blueThis 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.

i_round_blueIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

i_round_blueFor 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:

  • probehealthsensor

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 (i_priority_1) to the highest priority (i_priority_5).

i_round_blueUsually, a sensor connects to the IP Address/DNS Name of the parent device. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings.

Sensor Display

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.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary 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.
    i_round_redYou 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 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.

Inherited Settings

By default, all of the following 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 b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Scanning Interval

Click b_inherited_enabled to interrupt the inheritance.

Scanning Interval

Scanning Interval

Setting

Description

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:

  • 30 seconds
  • 60 seconds
  • 5 minutes
  • 10 minutes
  • 15 minutes
  • 30 minutes
  • 1 hour
  • 4 hours
  • 6 hours
  • 12 hours
  • 24 hours

i_round_blueYou can change the available intervals in the system administration of PRTG Network Monitor.

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:

  • Set sensor to down immediately: Set the sensor to the Down status immediately after the first request fails.
  • Set sensor to warning for 1 interval, then set to down (recommended): Set the sensor to the Warning status after the first request fails. If the second request also fails, the sensor shows the Down status.
  • Set sensor to warning for 2 intervals, then set to down: Set the sensor to the Down status only after the third request fails.
  • Set sensor to warning for 3 intervals, then set to down: Set the sensor to the Down status only after the fourth request fails.
  • Set sensor to warning for 4 intervals, then set to down: Set the sensor to the Down status only after the fifth request fails.
  • Set sensor to warning for 5 intervals, then set to down: Set the sensor to the Down status only after the sixth request fails.

i_round_blueSensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval before they show the Down status. It is not possible to immediately set a WMI sensor to the Down status, so the first option does not apply to these sensors. All other options can apply.

i_round_blueIf you define error limits for a sensor's channels, the sensor immediately shows the Down status. None of the interval options apply.

i_round_blueIf a channel uses lookup values, the sensor immediately shows the Down status. None of the interval options apply.

Access Rights

Click b_inherited_enabled to interrupt the inheritance.

Access Rights

Access Rights

Setting

Description

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:

  • Inherited: Inherit the access rights settings of the parent object.
  • No access: Users in this user group cannot see or edit the sensor. The sensor neither shows up in lists nor in the device tree.
  • Read access: Users in this group can see the sensor and view its monitoring results. They cannot edit any settings.
  • Write access: Users in this group can see the sensor, view its monitoring results, and edit its settings. They cannot edit its access rights settings.
  • Full access: Users in this group can see the sensor, view its monitoring results, edit its settings, and edit its access rights settings.

i_square_cyanFor more details on access rights, see section Access Rights Management.

Channel Unit Configuration

Click b_inherited_enabled to interrupt the inheritance.

Channel Unit Configuration

Channel Unit Configuration

Setting

Description

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, you can inherit these settings to all sensors underneath. You can set units for the following channel types (if available):

  • Bandwidth
  • Memory
  • Disk
  • File
  • Custom

i_round_blueCustom channel types are only available on sensor level.

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the monitored device, the available components, and the sensor setup.

Channel

Description

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%.

i_round_blueThis channel is the primary channel by default.

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.

More

i_square_blueKNOWLEDGE BASE

My probe system is running out of disk space. What can I do?

What security features does PRTG include?

Sensor Settings Overview

For more information about sensor settings, see the following sections: