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

The Python Script Advanced sensor executes a Python script on the computer running the local or remote probe. This option is provided as part of the PRTG Application Programming Interface (API). The return value of this sensor must be valid JSON or XML. For details about the return value format please see the Application Programming Interface (API) Definition.

PRTG includes a CPython 3.4.2 interpreter to execute Python scripts for this sensor type. Because of this you do not have to install anything manually to use the Python Script Advanced sensor. Your Python scripts must be compatible to Python 3 to run with this interpreter. It is located in the the \Python34 subfolder of your PRTG program directory. You can find the paepy package to easily create PRTG API conforming JSON output in the \Python34\Lib\site-packages folder.

  • The sensor can show values returned by the Python script in multiple channels.
Python Script Advanced Sensor

Python Script Advanced Sensor

Click here to enlarge: http://media.paessler.com/prtg-screenshots/python_script_advanced.png

Remarks

  • You must store the script file on the system of the probe on which you create the sensor: If used on a remote probe, you must store the file on the system running the remote probe. In a cluster setup, copy the file to every cluster node.
  • For best sensor usage we recommend that the return value is JSON encoded.
  • The timeout of the sensor is its scanning interval minus 1 second. Ensure your Python script does not run longer than this.
  • Print commands in the Python script are not supported and lead to an invalid JSON result.
  • Exceptions in the script are not supported.
  • Sensor channel values greater than 2^62 are not supported.
  • We recommend Windows 2012 R2 on the probe system for best performance of this sensor.

 

Limited to 50 Sensor Channels

PRTG does not support more than 50 sensor channels officially. Depending on the data used with this sensor type, you might exceed the maximum number of supported sensor channels. In this case, PRTG will try to display all sensor channels. However, please be aware that you will experience limited usability and performance.

Add Sensor

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

The following settings for this sensor differ in the 'Add Sensor' dialog in comparison to the sensor's settings page.

Sensor Settings

Python Script

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

This list shows all Python script files available in the \Custom Sensors\python sub-directory of the probe system's PRTG program directory (see Data Storage). To appear in this list, please store the files into this folder ending in 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.

For detailed information on how to build custom sensors and for the expected return format, please see the API documentation (Application Programming Interface (API) Definition). There, find detailed information on the Custom Sensors tab.

Note: When using custom sensors on the Cluster Probe, please copy your files to every cluster node installation.

Sensor Settings

On the details page of a sensor, click on the Settings tab to change its settings.

Note: Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created this sensor. See the Device Settings for details. For some sensor types, you can define the monitoring target explicitly in the sensor settings. Please see below for details on available settings.

Basic Sensor Settings

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 this sensor inherits from its parent device, group, and probe. This setting is shown for your information only and cannot be changed here.

Tags

Enter one or more Tags, separated by space or comma. You can use tags to group sensors and use tag–filtered views later on. Tags are not case sensitive. We recommend that you use the default value.

You can add additional tags to it, if you like. Other tags are automatically inherited from objects further up in the device tree. These are visible above as Parent Tags.

Priority

Select a priority for the sensor. This setting determines where the sensor is placed in sensor lists. Top priority is at the top of a list. Choose from one star (low priority) to five stars (top priority).

Sensor Settings

Python Script

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

Security Context

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

  • Use security context of probe service: Run the selected file under the same Windows user account the probe is running on. 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. Please navigate to parent device settings of this sensor to change these Windows credentials.

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. Please navigate to parent device settings of this sensor to change these credentials. Choose between:

  • Do not transmit device credentials: No device credentials are given to the script.
  • Transmit Windows credentials: Windows credentials are given to the script.
  • Transmit Linux credentials: Linux credentials are given to the script.
  • Transmit SNMP credentials: SNMP credentials are given to the script.
  • Transmit all device credentials: Windows, Linux, and SNMP credentials are all given to the script.

Note: All 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.

Please enter a string or leave the field empty.

Note: All parameters are transmitted in plain text.

Mutex Name

Define any desired mutex name for the process. All script sensors having the same mutex name will be 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. For links to more information, please see the More section below. Please enter a string or leave the field empty.

Debug Options

Sensor Result

Define what PRTG will do with the sensor results. Choose between:

  • Discard sensor result: Do not store the sensor result.
  • Write sensor result to disk (Filename: "Result of Sensor [ID].txt"): Store the last result received from the sensor to the "Logs (Sensor)" directory (on the Master node, if in a cluster). File names: Result of Sensor [ID].txt and Result of Sensor [ID].Data.txt. This is for debugging purposes. PRTG overrides these files with each scanning interval. For more information on how to find the folder used for storage, please see the Data Storage section.

Note: You can use Write sensor result to disk to inspect the passed JSON object that contains all parameters. This way you can find out which key you can access when you script.

Note: Transmitted passwords are masked in the log file.

Sensor Display

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 will always be displayed below the sensor's name. The available options depend on what channels are available for this sensor. Note: You can set another primary channel later by clicking on the pin symbol of a channel in the sensor's Overview tab.

Graph Type

Define how different channels will be shown for this sensor.

  • Show channels independently (default): Show an own 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 will generate an easy-to-read graph which visualizes the different components of your total traffic. Note: This option cannot be used in combination with manual Vertical Axis Scaling (available in the Sensor Channels Settings settings).

Stack Unit

This setting is only available if stacked graphs are selected above. Choose a unit from the list. All channels with this unit will be 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 following settings are inherited from objects higher in the hierarchy and should be changed there, if necessary. Often, best practice is to change them centrally in the Root group's settings. To change a setting only for this object, disable inheritance by clicking on the check mark before the corresponding setting name. You will then see the options described below.

Scanning Interval

Scanning Interval

Select a scanning interval (seconds, minutes, or hours) from the list. The scanning interval determines the time the sensor waits between two scans. You can change the available intervals in the system administration on PRTG on premises installations.

When a Sensor Reports an Error

Define the number of scanning intervals that a sensor has time to report an error before the sensor will be set to a Down status. The sensor can try to reach a device several times, depending on the setup you can specify here, to help avoid false alarms if the monitored device has only temporary issues. For previous scanning intervals with failed requests, the sensor will show a Warning status. Choose between:

  • Set sensor to "down" immediately: The sensor will show an error immediately after the first failed request.
  • Set sensor to "warning" for 1 interval, then set to "down" (recommended): After the first failed request, the sensor will show a yellow warning status. If the following request also fails, the sensor will show an error.
  • Set sensor to "warning" for 2 intervals, then set to "down": Show an error status only after three continuously failed requests.
  • Set sensor to "warning" for 3 intervals, then set to "down": Show an error status only after four continuously failed requests.
  • Set sensor to "warning" for 4 intervals, then set to "down": Show an error status only after five continuously failed requests.
  • Set sensor to "warning" for 5 intervals, then set to "down": Show an error status only after six continuously failed requests.

Note: Sensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval until they show an error. It is not possible to set a WMI sensor "down" immediately, so the first option will not apply to these sensor types (all other options can apply).

Note: If a sensor has defined error limits for channels, this sensor will always be set to a Down status immediately, so no "wait" option will apply.

Note: If a channel uses lookup values, the sensor will always be set to a Down status immediately, so no "wait" options will apply.

Schedules, Dependencies, and Maintenance Window

Note: Inheritance for schedules, dependencies, and maintenance windows cannot be interrupted. The corresponding settings from the parent objects will always be active. However, you can define additional settings here. They will be active at the same time as the parent objects' settings.

Schedule

Select a schedule from the list. Schedules can be used to monitor for a certain time span (days, hours) every week. With the period list option it is also possible to pause monitoring for a specific time span. You can create new schedules and edit existing ones in the account settings.

Note: Schedules are generally inherited. New schedules will be added to existing ones, so all schedules are active at the same time.

Maintenance Window

Specify if you want to set up a one-time maintenance window. During a "maintenance window" period, this object and all child objects will not be monitored. They will be in a paused state instead. Choose between:

  • Not set (monitor continuously): No maintenance window will be set and monitoring will always be active.
  • Set up a one-time maintenance window: Pause monitoring within a maintenance window. You can define a time span for a monitoring pause below and change it even for a currently running maintenance window.

Note: To terminate a current maintenance window before the defined end date, change the time entry in Maintenance Ends field to a date in the past.

Maintenance Begins

This field is only visible if you enabled the maintenance window above. Use the date time picker to enter the start date and time of the maintenance window.

Maintenance Ends

This field is only visible if you enabled the maintenance window above. Use the date time picker to enter the end date and time of the maintenance window.

Dependency Type

Define a dependency type. Dependencies can be used to pause monitoring for an object depending on the status of another. You can choose between:

  • Use parent: Pause the current sensor if the device, where it is created on, is in Down status, or is paused by another dependency.
  • Select object: Pause the current sensor if the device, where it is created on, is in Down status, or is paused by another dependency. Additionally, pause the current sensor if a specific other object in the device tree is in Down status, or is paused by another dependency. Select below.
  • Master object for parent: Make this sensor the master object for its parent device. The sensor will influence the behavior of the device, where it is created on: If the sensor is in Down status, the device will be 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 will be paused if the parent group of its parent device is in Down status, or if it is paused by another dependency.

Note: Testing your dependencies is easy! Simply choose Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later all dependent objects should be paused. You can check all dependencies in your PRTG installation by selecting Devices | Dependencies from the main menu bar.

Dependency

This field is only visible if the Select object option is enabled above. Click on the reading-glasses and use the object selector to choose an object on which the current sensor will depend.

Dependency Delay (Sec.)

Define a time span in seconds for a dependency delay. After the master object for this dependency goes back to Up status, PRTG will start monitoring the depending objects after this extra delayed. This can help to avoid false alarms, for example, after a server restart, by giving systems more time for all services to start up. Please enter an integer value.

Note: This setting is not available if you choose this sensor to Use parent or to be the Master object for parent. In this case, please define delays in the parent Device Settings or in the superior Group Settings.

Access Rights

User Group Access

Define which user group(s) will have access to the object you're editing. A table with user groups and types of access rights is shown: It contains all user groups from your setup. For each user group you can choose from the following access rights:

  • Inherited: Use the access rights settings of the parent object.
  • None: Users in this group cannot see or edit the object. The object neither shows up in lists nor in the device tree. Exception: If a child object is visible to the user, the object is visible in the device tree, though not accessible.
  • Read: Users in this group can see the object and review its monitoring results.
  • Write: Users in this group can see the object, review its monitoring results, and edit the object's settings. They cannot edit access rights settings.
  • Full: Users in this group can see the object, review its monitoring results, edit the object's settings, and edit access rights settings.

You can create new user groups in the System Administration—User Groups settings. To automatically set all objects further down in the hierarchy to inherit this object's access rights, set a check mark for the Revert children's access rights to inherited option.

For more details on access rights, please see the section User Access Rights.

Channel Unit Configuration

Channel Unit Types

For each type of sensor channel, define the unit in which data is displayed. If defined 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

Note: Custom channel types can be set on sensor level only.

More

Knowledge Base: What is the Mutex Name in PRTG's EXE/Script Sensor's settings?

Edit Sensor Channels

To change display settings, spike filter, and limits, switch to the sensor's Overview tab and click the gear icon of a specific channel. For detailed information, please see the Sensor Channels Settings section.

Notifications

Click the Notifications tab to change notification triggers. For detailed information, please see the Sensor Notifications Settings section.

Others

For more general information about settings, please see the Object Settings section.

Sensor Settings Overview

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

Keywords: