<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: Python Script Advanced Sensor

The Python Script Advanced sensor executes a Python script on the probe system. This option is provided as part of the PRTG API. The return value of this sensor must be valid JavaScript Object Notation (JSON) or Extensible Markup Language (XML).

The sensor can show the following:

  • Values returned by the Python script in multiple channels
Python Script Advanced Sensor

Python Script Advanced Sensor

Sensor in Other Languages

  • Dutch: Python Script Geavanceerd
  • French: Paramètres du capteur avancé
  • German: Python-Skript (Erweitert)
  • Japanese: Python スクリプト(上級)
  • Portuguese: Script Python Avançado
  • Russian: Python Скрипт (Дополнительно)
  • Simplified Chinese: Python 脚本高级
  • Spanish: Secuencia de comandos Python avanzada

Remarks

  • You must store the script file on the probe system. In a cluster, copy the file to every cluster node.
  • This sensor does not officially support more than 50 channels. Depending on the data used with this sensor, you might exceed the maximum number of supported channels. In this case, PRTG tries to display all channels. Be aware, however, that you experience limited usability and performance.
  • PRTG uses its own Python environment. This is located in the \python subfolder of the PRTG program directory. To avoid issues, we recommend that you do not have other Python environments running on a probe system. We also recommend that you do not uninstall the prtg Python package.
  • Print commands in the Python script are not supported and lead to an invalid JSON result.
  • Exceptions in the script are not supported.
  • Channel values greater than 2^62 are not supported.
  • The timeout of the sensor is its scanning interval minus 1 second. Ensure that your Python script does not run longer than this.
  • For best sensor usage, we recommend that the return value is JSON encoded.
  • We recommend Windows 2012 R2 on the probe system for best performance of this sensor.
  • This sensor has a medium performance impact.

i_podYou cannot add this sensor to the hosted probe of a PRTG hosted by Paessler instance. If you want to use this sensor, add it to a remote probe device.

Add Sensor

The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you do not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.

The following settings in the Add Sensor dialog differ in comparison to the sensor's Settings tab.

Sensor Settings

Setting

Description

Python Script

Select a Python script from the list. The sensor executes it with every scanning interval.

This list shows all Python script files available in the \Custom Sensors\python subfolder of the PRTG program directory on the probe system. For the files to appear in this list, store the files in this subfolder with the extension .py. To show the expected values and sensor status, your files must return the expected XML or JSON format to standard output. Values and message must be embedded in the XML or JSON. We recommend JSON-encoded return values.

i_square_cyanFor detailed information on how to build custom sensors and for the expected return format, see section Custom Sensors.

i_round_redWhen using custom sensors on the cluster probe, copy your files to every cluster node.

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.

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:

  • pythonxml
  • python
  • xml
  • json
  • script

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 Settings

Setting

Description

Python Script

Shows the Python script file that the sensor executes with each scan as defined at sensor creation. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew.

Security Context

Define the Windows user account that the sensor uses to run the Python interpreter:

  • Use security context of probe service: Run the selected file under the same Windows user account that the probe runs under. By default, this is the Windows system user account (if not manually changed).
  • Use Windows credentials of parent device: Use the Windows user account defined in the settings of the parent device on which you create this sensor. You can change these Windows credentials in the parent device settings of this sensor.

Device Credentials

Define if you want to transmit device credentials to the Python script. PRTG adds the device credentials to the JSON object that is passed to the script as command-line parameter. You can change these Windows credentials in the parent device settings of this sensor. Choose between:

  • Do not transmit device credentials: No device credentials are transmitted to the script.
  • Transmit Windows credentials: Windows credentials are transmitted to the script.
  • Transmit Linux credentials: Linux credentials are transmitted to the script.
  • Transmit SNMP credentials: SNMP credentials are transmitted to the script.
  • Transmit all device credentials: Windows, Linux, and Simple Network Management Protocol (SNMP) credentials are all transmitted to the script.

i_round_blueAll parameters are transmitted in plain text.

Additional Parameters

Define additional parameters to add to the JSON object that is passed to the script as command-line parameter. Enter a string or leave the field empty.

i_round_blueAll parameters are transmitted in plain text.

Mutex Name

Define any desired mutual exclusion (mutex) name for the process. All script sensors that have the same mutex name are executed serially (not simultaneously). This is useful if you use a lot of sensors and want to avoid high resource usage caused by processes running simultaneously. Enter a string or leave the field empty.

i_square_cyanFor more details, see the Knowledge Base: What is the Mutex Name in the PRTG EXE/Script Sensor settings?

Debug Options

Setting

Description

Sensor Result

Define what PRTG does with the sensor results:

  • Discard sensor result: Do not store the sensor result.
  • Write sensor result to disk (file names: Result of Sensor [ID].*): Store the last result received from the sensor to the \Logs\sensors subfolder of the PRTG data directory on the probe system (master node, if in a cluster). File names: Result of Sensor [ID].* and Result of Sensor [ID].Data.*. This is for debugging purposes. PRTG overwrites these files with each scanning interval.
    i_podThis option is not available when the sensor runs on the hosted probe of a PRTG hosted by Paessler instance.

i_round_blueYou can use Write sensor result to disk to inspect the passed JSON object that contains all parameters (PRTG on premises only). This way, you can find out which key you can access when you script.

i_round_blueTransmitted passwords are masked in the logfile.

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.

Schedules, Dependencies, and Maintenance Window

i_round_blueYou cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.

Setting

Description

Schedule

Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:

  • None
  • Saturdays
  • Sundays
  • Weekdays
  • Weekdays Eight-To-Eight (08:00 - 20:00)
  • Weekdays Nights (17:00 - 09:00)
  • Weekdays Nights (20:00 - 08:00)
  • Weekdays Nine-To-Five (09:00 - 17:00)
  • Weekends

i_square_cyanYou can create schedules, edit schedules, or pause monitoring for a specific time span. For more information, see section Schedules.

Maintenance Window

Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:

  • Not set (monitor continuously): Do not set up a one-time maintenance window. Monitoring is always active.
  • Set up a one-time maintenance window: Set up a one-time maintenance window and pause monitoring. You can define a time span for a the pause below.

i_round_blueTo terminate an active maintenance window before the defined end date, change the time entry in Maintenance Ends to a date in the past.

Maintenance Begins

This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window.

Maintenance Ends

This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window.

Dependency Type

Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:

  • Use parent: Use the dependency type of the parent object.
  • Select a sensor: Use the dependency type of the parent object. Additionally, pause the current object if a specific sensor is in the Down status or in the Paused status because of another dependency.
  • Master sensor for parent: Make this sensor the master object for its parent device. The sensor influences the behavior of its parent device: If the sensor is in the Down status, the device is paused. For example, it is a good idea to make a Ping sensor the master object for its parent device to pause monitoring for all other sensors on the device in case the device cannot even be pinged. Additionally, the sensor is paused if the parent group is paused by another dependency.

i_round_blueTo test your dependencies, select Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later, all dependent objects are paused. You can check all dependencies under Devices | Dependencies in the main menu bar.

Dependency

This setting is only visible if you enable Select a sensor above. Click b_search_light and use the object selector to select a sensor on which the current object will depend.

Dependency Delay (Sec.)

This setting is only visible if you enable Select a sensor above. Define a time span in seconds for the dependency delay.

After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.

i_round_redThis setting is not available if you set this sensor to Use parent or to be the Master sensor for parent. In this case, define delays in the parent device settings or in its parent group settings.

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_bluePRTG MANUAL

 

i_square_blueKNOWLEDGE BASE

What is the Mutex Name in the EXE/Script Sensor settings?

Why do I have to store SQL sensor queries and custom scripts in files on the probe computer?

Sensor Settings Overview

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