<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: System Administration—Monitoring

This option is not available in PRTG on demand.

Available Intervals

Define the intervals available in the dropdown list of every object's settings. In the text field, enter one value in each line. Use s, m, h, and d for defining seconds, minutes, hours, and days. By default, there are the following scanning intervals defined:

30s: 30 seconds

1m: 1 minute

5m: 5 minutes

10m: 10 minutes

15m: 15 minutes

30m: 30 minutes

1h: 1 hour

4h: 4 hours

6h: 6 hours

12h: 12 hours

1d: 1 day

We recommend that you do not use intervals shorter than 10 seconds to prevent system overload. Intervals below 10 seconds are not officially supported! The maximum supported scanning interval is 10 days.

You can also define specific points in time to indicate when PRTG executes scanning actions. Enter up to 50 concrete UTC points in time according to the formula

@ UTC hh:mm, hh:mm

Your local time may be different from the UTC time!

 
For more information on how to set specific points in time as a scanning time for sensors, see this Knowledge Base article: Can I set a sensor to run at a specific time?

The unusual detection can set sensors to an Unusual status when there are values that are untypical for the time span in which they are measured. PRTG compares the current average values to the historic monitoring results for this purpose. If the current values show a big difference to the values that are normally retrieved by a sensor, this sensor will indicate this with the unusual status.

You can define the granularity of the unusual detection here (this means, how big the difference must be to cause an unusual status). If you disable the unusual detection (both settings to Never), sensors will never show an unusual status.

You can enable and disable unusual detection for specific devices, entire groups, and probes in the respective Object Settings.

Show Unusual When

Define when a sensor shows the unusual status, comparing the weekday. If you enable the detection here, the average of the values which were measured on the day before is compared to the average of the same weekday in previous weeks. Choose between:

• Never: Disable unusual detection for weekday average.
• 24h average is <80% or >120% of weekday average: The average of the values measured on the day before is either lower than 80% or higher than 120% than usually on the same weekday.
• 24h average is <50% or >200% of weekday average: The average of the values measured on the day before is either lower than 50% or higher than 200% than usually on the same weekday.
• 24h average is <20% or >500% of weekday average (recommended): The average of the values measured on the day before is either lower than 20% or higher than 500% than usually on the same weekday.
• 24h average is <10% or >1,000% of weekday average: The average of the values measured on the day before is either lower than 10% or higher than 1,000% than usually on the same weekday.
• 24h average is <1% or >10,000% of weekday average: The average of the values measured on the day before is either lower than 1% or higher than 10,000% than usually on the same weekday.

For example, consider a traffic sensor that usually measures 100 MB average traffic on a weekday. If you choose the first option, it would show an unusual status if the average from the day before is below 80 MB or above 120 MB.

Show Unusual When

Define when a sensor shows the unusual status, comparing the hour-of-day. If you enable the detection here, the average of the values which were measured in the hour before is compared to the average of the same hour on the same weekday in previous weeks. Choose between:

• Never: Disable unusual detection for hour-of-day average.
• Hourly average is <80% or >120% of hour-of-day average: The average of the values measured in the hour before is either lower than 80% or higher than 120% than usually in this hour of this weekday.
• Hourly average is <50% or >200% of hour-of-day average: The average of the values measured in the hour before is either lower than 50% or higher than 200% than usually in this hour of this weekday.
• Hourly average is <20% or >500% of hour-of-day average (recommended): The average of the values measured in the hour before is either lower than 20% or higher than 500% than usually in this hour of this weekday.
• Hourly average is <10% or >1,000% of hour-of-day average: The average of the values measured in the hour before is either lower than 10% or higher than 1,000% than usually in this hour of this weekday.
• Hourly average is <1% or >10,000% of hour-of-day average: The average of the values measured in the hour before is either lower than 1% or higher than 10,000% than usually in this hour of this weekday.

Consider a traffic sensor that usually measures 10 MB average traffic within an hour. If you choose the first option, it would show an unusual status if the average from the hour before is below 8 MB or above 12 MB.

Logging

Define if unusual events will be written to the log file. Choose between:

• Do not log unusual events
• Write unusual events into the log

Similar sensors detection enables PRTG to analyze sensor data for similarities. The detection will run in the background with low priority. The recommended setting for similar sensors detection is to let PRTG automatically decide how many channels will be analyzed. However, you can also override this setting.

When similar sensors analysis is turned off or you have exceeded 1,000 sensors and have chosen the automatic analysis depth option, the similar sensors entry will not be shown in the main menu bar.

Analysis Depth

Define the number of channels PRTG will analyze to detect similarities between sensors or turn the analysis off. Choose between:

• Manage automatically based on sensor count (recommended): The analysis depth depends on the total number of sensors you have configured. PRTG will analyze all channels for up to 500 sensors, and only the primary sensor channels for up to 1,000 sensors. If exceeding 1,000 sensors, the analysis will be turned off.
• Analyze primary channels only: Only the primary channels of sensors are analyzed. Be aware of potentially high CPU load of PRTG when choosing this setting for more than 1,000 sensors.
• Analyze all channels (higher CPU load): Similarity detection is applied to all channels. Be aware of potentially high CPU load of PRTG when choosing this setting for more than 500 sensors.
• Turn analysis off: No similarity detection takes place. Choose this option if you are not interested in the analysis results or you want to keep the CPU load of PRTG at a minimum.

With the sensor recommendation engine, PRTG can analyze devices in your network and suggest sensors that are still missing for a complete monitoring. The analysis runs with low priority in the background when you add a new device, when the last analysis was executed more than 30 days ago, or when you manually start it.

See the manual section Recommended Sensors for more information, for example, on SNMP settings, on the results you get and on how you add the suggested sensors.

This option is not available in PRTG on demand.

Detection Engine

Define if you want PRTG to analyze your devices to recommend useful sensor types. Choose between:

• Manage automatically based on sensor count (recommended): PRTG runs the detection engine for installations with up to 5,000 sensors by default. If you exceed this threshold, PRTG disables the detection engine for performance reasons. We recommend that you set this option so you do not miss any important monitoring data about your network, without risking to run into performance issues.
• Always show recommendations: PRTG always analyzes your devices even if your installation exceeds 5,000 sensors and you will never miss any suggestion to complete your monitoring. But if you enable this option, please keep in mind this setting in case you encounter performance issues.
• Turn recommendations off: PRTG never recommends sensors. Select this option if you have performance issues with PRTG or if you do not want to see this information on device overview tabs. Moreover, you will not find the option Recommend Now in device context menus or on overview tabs anymore.

Run Discovery at

Define the time when PRTG automatically runs an Auto-Discovery in your network if you configured a daily or weekly Discovery Schedule in the auto-discovery group settings. Choose a full hour between 0:00 and 23:00. We recommend that you choose a time when there is little user activity in your network, because auto-discoveries can produce a certain amount of load.

Desired Minimum Uptime

Define which uptime in percent PRTG regards as 100 percent. This setting affects the colors shown next to the sensor icons in reports. Select one of the predefined values between 90 % and 99.999 %.