PRTG Manual: File Content Sensor

The File Content sensor checks a text file (for example, logfiles) for certain strings and returns the following:

  • Line number of the last match
  • Number of total matches.
  • Additionally, the sensor quotes matching lines in the sensor message field.
File Content Sensor

File Content Sensor

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

Remarks

  • This sensor does not support UTF-16 encoded files! In this case, please try use a custom sensor like the EXE/Script Sensor or the EXE/Script Advanced Sensor.
  • This sensor does not officially support binary files! If you would still like to monitor binary files contrary to our recommendation, then please choose the option Always transmit to PRTG the entire file in section Network Usage in the sensor settings.
  • This sensor supports Unix line feeds.
  • Requires the LanmanServer ("Server") Windows service to be running on the target computer to monitor files on a share.
  • To monitor files on a Linux system, the folder has to be accessible via SMB.
  • Try using the Fully Qualified Domain Name (FQDN) of the target device if the sensor does not get a connection with the IP address.
  • This sensor type can have a high impact on the performance of your monitoring system. Please use it with care! We recommend that you use no more than 50 sensors of this sensor type on each probe.

icon-prtg-on-demandYou cannot add this sensor type to cloud probes in PRTG in the cloud. If you want to use this sensor type, please add it to a remote probe device.

Requirement: LanmanServer ("Server") Windows Service

icon-toolsTo monitor files on Windows shares, please make sure the LanmanServer ("Server") Windows service is running on the target computer.

To enable the service, please log in to the respective computer and open the services manager (for example, via services.msc). In the list, find the respective service and set its Start Type to Automatic.

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 will not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.

Sensor Settings

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

icon-i-roundUsually, a sensor connects to the IP Address or DNS Name of the parent device where 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 spaces or commas. 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 the sensor 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 Specific

File Name

Enter the full path to the file that this sensor will monitor. For example, enter C:\Windows\file.txt. to monitor a file on the parent probe system.

If you use a local path, the sensor looks for the target file only on the system on which the parent probe runs, not on the parent device! To monitor a file on the parent device, use the dollar sign ($) like C$\User\johnqpublic\file.txt.

If the file is located on a network device, use the Uniform Naming Convention (UNC) path without the server part (only enter share\folder\file.txt). The server part (\\server\) is taken from the parent device settings of this sensor. Enter a valid path and file name.

icon-i-round-redTo provide any Windows shares, the LanmanServer "Server" Windows service must run on the target computer.
 

icon-i-round-redTo monitor any Linux files, the folder with these files has to be accessible via Server Message Block (SMB).
 

icon-i-redPlease be aware that it might produce high network traffic if you define PRTG to query an entire file on your network with every scanning interval.

Search String

Define the string inside the logfile you want to check for. The input is not case-sensitive. Please enter a string.

Search Method

Define the method you want to provide the search string with. The pattern must be in one line and only the last matching line will be given back. Choose between:

  • Simple string search: Search for a simple plain text expression.
  • Regular Expression: Search using a regular expression.
     

icon-i-roundPRTG supports PCRE regex. You cannot use regex options or flags. For more details, see manual section Regular Expressions.

Network Usage

Define in which way the sensor will transmit the target file to PRTG. Choose between:

  • Only transmit to PRTG new lines at the end of the file (default): This option improves the performance of the sensor. It sends the whole file only with the first scan to PRTG. With the following sensor scans, the sensor will only transmit lines which were appended since the last scan. All other lines (which already existed in the previous scan) are not sent. The sensor assumes that they are unchanged and still counts them.
    icon-betaThis option is currently in beta status. Please do not expect that it will work as expected in every usage scenario!
     
  • Always transmit to PRTG the entire file: The sensor sends the whole file with every sensor scanning interval to PRTG. If this results in too much traffic on the target system, we recommend that you choose the new lines option.

The sensor can only transmit newly added lines in the following cases:

  • the file is bigger than at the previous scan, and
  • the last line in the file at the previous scan still has to be at the same place in the file.

icon-i-roundThe sensor supports Windows and Linux line endings (CRLF or. LF).

File Encoding

Specify the encoding of the file that this sensor monitors. Choose between:

  • Windows-1252
  • UTF-8
  • UTF-16

Warning Behavior

Define under which condition the sensor will show a Warning status. Choose between:

  • Go into warning status when string is not found: The sensor will show a Warning status if there is no match. Otherwise it will remain in Up status.
  • Go into warning status when string is found: The sensor will show a Warning status if there is a match. Otherwise it will remain in Up status.

If Value Changes

Define what this sensor will do when the sensor value changes. You can choose between:

  • Ignore changes (default): The sensor takes no action on change.
  • Trigger 'change' notification: The sensor sends an internal message indicating that its value has changed. In combination with a Change Trigger, you can use this mechanism to trigger a notification whenever the sensor value changes.

icon-i-round-redThe change notification for this sensor is triggered if the value of the channel Last occurrence (line) changes. It is not triggered when the number of Matches changes.

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 in the PRTG data folder on the probe system the sensor is running on (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.
    icon-book-arrowsFor more information on how to find the folder used for storage,
    see section Data Storage.

icon-prtg-on-demandThis option is not available on cloud probes in PRTG in the cloud.

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.

icon-i-roundYou can set another primary channel later by clicking 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 that visualizes the different components of your total traffic.
    icon-i-roundThis 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 the check mark in front of 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.

If a Sensor Query Fails

Define the number of scanning intervals that a sensor has time reach and check a device again in case a sensor query fails. The sensor can try to re-reach and check a device several times, depending on the option you select here, before it will be set to a Down status. This helps you 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.

icon-i-roundSensors 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 to "down" immediately, so the first option will not apply to these sensor types. All other options can apply.

icon-i-roundIf a sensor has defined error limits for channels, it will always show a Down status immediately, so no "wait" option will apply.
 

icon-i-roundIf a channel uses lookup values, it will always show a Down status immediately, so no "wait" options will apply.

Schedules, Dependencies, and Maintenance Window

icon-i-roundInheritance 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.

icon-i-roundSchedules 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.

icon-i-roundTo 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.

icon-i-roundTesting 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.

icon-i-round-redThis 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.

icon-book-arrowsFor more details on access rights, please see the section User Access Rights.

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: