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

Sensor Name

Enter a 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.

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?

Parent Tags

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

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:

• 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 () to the highest priority ().

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 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.

Age of Code

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.

This channel has a default limit

• Upper warning limit: 7776000 seconds

Committed Memory

The amount of memory committed to the PRTG core server as reported by the memory manager

Configuration Last Saved

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 warns 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.

This channel has a default limit

• Upper warning limit: 93600 seconds

CPU Load

The CPU load (%). 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

Free Page File Memory

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

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

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.

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 PRTG core server state as a value between 100% (healthy) and 0% (failing). Investigate frequent or repeated health values below 100%.

This channel is the primary channel by default.

Maintenance Days

The remaining maintenance days of your PRTG Network Monitor license. Renew your maintenance in time to make sure that you get updates for PRTG Network Monitor. PRTG Hosted Monitor shows a fixed value here for technical reasons.

This channel has default limits

• Lower error limit: 0
• Lower warning limit: 30

Notifications in Send Queue

The number of notifications that are in the send queue

Number of State Objects

The number of user-specific state objects that are found in the memory of the PRTG core server system

Probe Messages per Second

The number of messages sent from all probes to the PRTG core server

Raw Data Buffer

The amount of raw data that is temporarily stored on the physical memory during I/O operations on the disk. Usually, this value should be 0 (or very low). Investigate increasing values.

Threads

The number of program parts that are running simultaneously. This number can increase with heavy load. Usually, this number should not exceed 100.