<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: PostgreSQL Sensor

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).

Database

Enter the name of the PostgreSQL database to which the sensor connects. For example, such a database's name could be MyDatabase. This is a logical entity on the database server where database objects like tables or stored procedures exist.

SSL Mode

Select the PostgreSQL SSL mode for the sensor connection. PostgreSQL SSL connections require OpenSSL to be installed on both the target server and on the PRTG probe system with this sensor. The SSL mode options you can choose here are the same as the values of the PostgreSQL sslmode parameter. PRTG sends it with the sensor requests.

Choose between these SSL modes:

• Disable
• Allow
• Prefer
• Require

For details about the PostgreSQL SSL modes, please refer to the PostgreSQL documentation.

SQL Query File

Select an SQL script file that includes a valid SQL statement to execute on the server. 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.

The script will be executed with every scanning interval. The list contains SQL scripts from the database management system specific \Custom Sensors\sql subfolder of your PRTG installation. Store your script there. If used on a remote probe, the file must be stored on the system running the remote probe. If used on a cluster probe, you must store the file on all servers running a cluster node! For more information on how to find this path, please see Data Storage section. By default, there is the demo script Demo Serveruptime.sql available that you can use to monitor the uptime of the target server.

For example, a correct expression in the file could be: SELECT AVG(UnitPrice) FROM Products. If you want to use transactions, separate the individual steps with semicolons ";".

Note: Please be aware that with each request the full result set will be transferred, so use filters and limits in your query.

Use Transaction

Define if you want to use transactions and if they will affect the database content. Choose between:

• Don't use transaction (default): No transactions will be executed.
• Use transaction and always rollback: Choose this option to ensure that no data in the database will be changed by the query. In the SQL Query field above, separate the single steps of the transaction with semicolons.
• Use transaction and commit on success: Choose this option to perform changes on the database with the query. The changes will only apply if all execution steps succeed without any errors. In the SQL Query field above, separate the single steps of the transaction with semicolons.

Data Processing

Define if you want to process data from the database. 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. Choose between:

• Just execute the query: If you select this option, the sensor will only show information about the number of affected rows and the execution time of the query.
• Process data table: Select this option to read and analyze the queried data table.

Handle DBNull in Channel Values as

This setting is only visible if you selected the process data table option above. Define the sensor behavior if DBNull is returned by the query. Choose between:

• Error: The sensor will show a Down status if DBNull is reported.
• Number 0: The sensor will recognize the result DBNull as a valid value and interpret it as the number 0.

Select Channel Value by

This setting is only visible if you selected the process data table option above. Define how the desired cell in the database table will be selected. This is necessary to configure the cells which will be used in the sensor channels. Choose between:

• Column number: The channel value will be determined by using the value in row 0 of the column whose number you specify below.
• Column name: The channel value will be determined by using the value in row 0 of the column whose name you specify below.
• Row number: The channel value will be determined by using the value in column 0 of the row whose number you specify below.
• Key value pair: The channel value will be determined by searching in column 0 for the key you specify below and returning the value in column 1 of the same row where the key value was found.
   

Please see manual section Monitoring Databases for an example for channel value selection.

Sensor Channel #x

This setting is only visible if you selected the process data table option above. You can define up to 10 different channels for the data processing of this sensor. You have to define at least one data channel if you process the data table, so you will see all available settings for Channel #1 without enabling it manually. For all other possible channels, choose between:

• Disable: This channel will not be added to the sensor.
• Enable: This channel will be added to the sensor. Define the settings as described above.

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.

Sensor Channel #x Name

This setting is only visible if you selected the process data table option above. Enter a unique name for the channel. Please enter a string. Channels will be generated dynamically with this name as identifier. 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.

Sensor Channel #x Column Number

This setting is only visible if you selected the column number option above. Provide the number of the column which will be used to determine the channel value in row 0. Please enter an integer value.

Sensor Channel #x Column Name

This setting is only visible if you selected the column name option above. Provide the name of the column which will be used to determine the channel value in row 0. Please enter a string.

Sensor Channel #x Row Number

This setting is only visible if you selected the row number option above. Provide the number of the row which will be used to determine the channel value in column 0. Please enter an integer value.

Sensor Channel #x Key

This setting is only visible if you selected the key value pair option above. Provide the key to search for in column 0 of the data table. The value in column 1 of the same row where the key value was found will be used to determine the channel value. Please enter a string.

Sensor Channel #x Mode

This setting is only visible if you selected the process data table option above. Define how to display the determined value in the channel. 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. Choose between:

• Absolute (recommended): Shows the value as the sensor retrieves it from the data table.
• Difference: The sensor calculates and shows the difference between the last and the current value returned from the data table.

Sensor Channel #x Unit

This setting is only visible if you have selected the process data table option above. Define the unit of the channel value. 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. Choose between:

• BytesBandwidth
• BytesMemory
• BytesDisk
• Temperature
• Percent
• TimeResponse
• TimeSeconds
• TimeHours
• Count
• CPU
• BytesFile
• SpeedDisk
• SpeedNet
• Custom
• Value Lookup

For more information about the available units, please refer to the PRTG Application Programming Interface (API) Definition for custom sensors.

Sensor Channel #x Custom Unit

This setting is only visible if you selected the Custom unit option above. Define a unit for the channel value. Please enter a string.

Sensor Channel #x Value Lookup

This settings is only visible if you select the Value Lookup option above. Select a lookup file that you want to use with this channel.

Use Data Table Value in Sensor Message

This setting is only visible if you selected the process data table option above. Define if the sensor message will show a value from the data table. Choose between:

• Disable: Do not use a custom sensor message.
• Enable: Define a custom sensor message with the value of a defined channel.

Sensor Message Column Number

This setting is only visible if you selected the column number and sensor message options above. Specify the number of the column whose value will be shown in the sensor message. Please enter an integer value.

Sensor Message Column Name

This setting is only visible if you selected the column name and sensor message options above. Specify the name of the column whose value will be shown in the sensor message. Please enter a string.

Sensor Message Row Number

This setting is only visible if you selected the row number and sensor message options above. Specify the number of the row whose value will be shown in the sensor message. Please enter an integer value.

Sensor Message Key

This setting is only visible if you selected the key value pair and sensor message options above. Specify the key for the value which will be shown in the sensor message. Please enter a string.

Sensor Message

This setting is only visible if you selected the sensor message option above. Define the sensor message. Please enter a string. Use the placeholder {0} at the position where the value will be added.

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 name: Result of Sensor [ID].txt. This is for debugging purposes. The file will be overridden with each scanning interval. For more information on how to find the folder used for storage, please see the Data Storage section.

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.

Chart 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.

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.

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.

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) throughout the 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, you can change the time in Maintenance End At field to a date in the past.

Maintenance Begins At

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 End At

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 a Down status, or if the sensor is paused by another dependency.
• Select object: Pause the current sensor if the device, where it is created on, is in an Down status, or if the sensor is paused by another dependency. Additionally, pause the current sensor if a specific other object in the device tree is in a Down status, or if it 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 a 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 a 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.

Delay (Seconds)

Define a time span. After the master object for this dependency comes back to an Up status, the beginning of the monitoring of the depending objects will be additionally delayed by the time span you define here. 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 in seconds. Note: This setting is not available if you choose this sensor to be the Master object for parent. In this case, please define delays in the parent Device Settings or in the superior Group Settings.

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.