PRTG Manual: Core Health Sensor

The Core Health sensor monitors internal PRTG parameters. It shows the status of the PRTG core server.

The sensor checks various parameters of your PRTG core server that have an impact on the stability of the system:

  • Health: This index value sums up the core state as a value between 100% (healthy) and 0% (failing). Investigate frequent or repeated health values below 100%.
  • Age of Code: This channel shows the time that has passed since the last update of your PRTG core server. Update regularly to get the best security and stability for PRTG, as well as the latest features. We recommend that you use the auto-update to automatically get new versions.
  • CPU Load: This channel shows the CPU load in percent. Extensive CPU load can lead to false, incomplete, and incorrect monitoring results. This value should usually stay below 50%.
  • Handles: This is a counter for the data structures of the operating system. It is responsible for internal resource management. Investigate obviously increasing values that occur repeatedly.
  • Committed Memory: This channel shows the amount of memory committed to the PRTG core server as reported by the memory manager.
  • Configuration Last Saved: This channel shows the time passed since the configuration file was last saved successfully. PRTG saves the configuration every 24 hours. If the configuration cannot be saved, PRTG creates a ticket as soon as the saving process has failed, and warn you via this channel after 26 hours. None of your changes to PRTG can be saved if this happens. In this case, restart your PRTG core server to save the file.
  • Free Page File Memory: This channel shows the amount of free page file memory that is available on the system. Page file memory is aggregated RAM and the size of page file. It is the maximum amount of memory that is available on the system to be used for all running processes. If it gets too low, the system can break down, and at least some applications throw Out of memory errors.
  • Free Physical Memory: This channel shows the amount of free physical memory that is available on the system. This is the RAM that is physically built into the computer. If it gets too low, the system becomes very slow and PRTG no longer works in a useful way. Some sensors might not be displayed correctly and show the Unknown status.
  • Free Virtual Memory: This channel shows the address space on the system that PRTG can access. PRTG cannot use more memory than reported here, which is independent from free page file and physical memory. On a 32-bit operating system, the maximum is 2 GB (3 GB with special settings under Windows). On a 64-bit operating system, it is 4 GB if PRTG runs as a 32-bit version, and unlimited if it runs as a 64-bit version (PRTG core server only). If the free virtual memory gets too low, PRTG throws Out of memory errors or the message not enough storage to process this command. This message is visible in the Core log.
  • Maintenance Days: This channel shows the remaining maintenance days of your PRTG on premises license. Renew your maintenance in time to make sure that you get updates for your PRTG on premises installation. PRTG hosted by Paessler instances show a fixed value here for technical reasons.
  • Threads: This channel shows the number of program parts that are running simultaneously. This number can increase with heavy load. Usually, this number should not exceed 100.
  • Raw Data Buffer: This channel shows how much raw data is temporarily stored on the physical memory during input/output (I/O) operations on the disk. Usually, this value should be 0 (or very low). Investigate increasing values.
  • Probe Messages per Second: This channel shows the number of messages sent per second from all probes to the PRTG core server.
  • Notifications in Send Queue: This channel shows the number of notifications that are in the send queue.
  • Number of State Objects: This channel shows the number of user-specific state objects that are found in the PRTG core server system's memory.
Core Health Sensor

Core Health Sensor

Sensor in Other Languages

  • Dutch: Core Status
  • French: État du serveur central
  • German: Serverzustand
  • Japanese: コアの正常性
  • Portuguese: Funcionamento do servidor central
  • Russian: Работоспособность базового сервера
  • Simplified Chinese: 核心健康状况
  • Spanish: Salud del servidor central

Remarks

  • PRTG automatically creates this sensor. You cannot delete it.
  • You can only set up this sensor on a local probe device.
  • This sensor has a very low performance impact.

Basic Sensor Settings

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

i_round_blueUsually, 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

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. 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.

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

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • corehealthsensor

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).

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. You should 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. You then see the options described below.

i_square_cyanFor more information, see section Inheritance of Settings.

Scanning Interval

Click b_inherited_enabled to interrupt the inheritance.

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
  • 1 day

i_round_blueYou can change the available intervals in the system administration on PRTG on premises installations.

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.

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.

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, these settings can be inherited 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.

More

i_square_blueKNOWLEDGE BASE

What do the PRTG core memory parameters mean?

Sensor Settings Overview

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