PRTG Manual: HTTP Transaction Sensor

Sensor Name

Enter a 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.

If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

This setting is for your information only. You cannot change it.

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.

It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

For performance reasons, it can take some minutes until you can filter for new tags that you added.

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

▪httptransactionsensor

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 () to the highest priority ().

Timeout (Sec.)

Enter a timeout in seconds for all HTTP requests. Enter an integer. The maximum value is 900 seconds (15 minutes).

If the complete transaction takes longer than this value, the sensor cancels the request and shows an according error message. If two consecutive requests are unsuccessful (for whatever reason), the sensor shows the Down status.

Single URL Timeout (Sec.)

Enter a timeout in seconds for one single HTTP request. Enter an integer. The maximum value is 900 seconds (15 minutes).

If the reply of any single request takes longer than this value, the sensor cancels the transaction and shows an according error message.

Monitoring Engine

Choose the monitoring engine that the sensor uses:

▪Default engine (recommended): Use the default monitoring engine.

▪Compatibility engine: Execute an external executable program. Use this method as an alternative for websites that do not work with the default monitoring engine.
This method needs more resources but it can be helpful in some cases.
If you select the compatibility mode, the options for the SSL method are different. You can also check for trusted certificates. See below.
Smart URL Replacement does not work with the compatibility mode, so this sensor does not automatically use the IP Address/DNS Name of the parent device.

SSL/TLS Method

This option is only visible if you select Compatibility engine above. Choose from:

▪SSLv3

▪TLS 1.0, TLS 1.1, TLS 1.2

▪SSLv3, TLS 1.0, TLS 1.1, TLS 1.2 (default)

Check SSL Certificates

This option is only visible if you select Compatibility engine above. Specify if the sensor checks the certificate of the URL:

▪Do not check certificates (default): Do not check the certificates of the web pages.

▪Check if certificates are trusted: Check the certificates of the web pages. If the certificate of the server is not trusted, the sensor shows the Down status and displays a corresponding message.

Download Limit (KB)

Enter a number that defines the maximum amount of data (in kilobytes) that the sensor transfers per request.

If you set content checks, be aware that they might be incomplete. This is because the sensor only checks the content that is downloaded up to this limit for search expressions.

Cookie Management

Select if you want to allow cookies for the transaction:

▪Use cookies (recommended): Allow cookies to be set and read during the transaction cycle. We recommend that you use this option.

▪Ignore cookies: Do not allow cookies. Use this option if you want to test the transaction without the use of cookies.

User Agent

Choose which user agent string the sensor sends when it connects to the target URL:

▪Use the default string: Do not enter a specific user agent and use the default string. Usually, this is Mozilla/5.0 (compatible; PRTG Network Monitor (www.paessler.com); Windows).

▪Use a custom string: Use a custom user agent. Define the custom user agent below.

Custom User Agent

This setting is only visible if you enable Use a custom string above. Enter the string that the sensor uses as the user agent when it connects to the target URL.

Result Handling

Define what PRTG does with the web page that is loaded at the URL:

▪Discard result: Do not store the sensor result.

▪Store result: Store the last result of the web page in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID]-1.txt and Result of Sensor [ID].Data.txt. This setting is for debugging purposes, especially in combination with content checks. PRTG overwrites the files with each scanning interval.

This option is not available when the sensor runs on the hosted probe of a PRTG Hosted Monitor instance.

In a cluster, PRTG stores the result in the PRTG data directory of the master node.

Authentication

Define if authentication is necessary on the web page:

▪Web page does not need authentication

▪Web page needs authentication

User Name

If the proxy requires authentication, enter the user name for the proxy login.

Only basic authentication is available. Enter a string.

Password

This setting is only visible if you select Web page needs authentication above. Enter a password.

Authentication Method

This setting is only visible if you select Web page needs authentication above. Select the authentication method that the URL uses:

▪HTTP authentication: Use simple HTTP authentication.
This authentication method transmits credentials as plain text.

▪NT LAN Manager authentication: Use the Microsoft NT LAN Manager (NTLM) protocol for authentication.

▪Digest access authentication: Use digest access authentication. This applies a hash function to the password, which is safer than HTTP authentication.

Transaction Step #x

This setting is available for URL #2 through #10. Define if you want to use this step for the transaction check:

▪Disable step #x: Do not use this step. Choose this option if you do not need all 10 steps for the transaction check.

▪Enable step #x: Enable this step. Further options are available.

URL

Enter the URL that the sensor connects to. If you enter an absolute URL, the sensor uses this address independently of the IP Address/DNS Name setting of the parent device.

The URL must not be URL encoded.

PRTG uses a smart URL replacement with which you can use the parent device's IP address or Domain Name System (DNS) name setting as part of the URL. For more information, see section Smart URL Replacement.

Request Method

Select an HTTP request method to determine how the sensor requests the URL:

▪GET: Directly request the website.
We recommend that you use this setting for a simple check of the web page.

▪POST: Send post form data to the URL.
If you select this setting, you must enter the data in the Postdata field below.

▪HEAD: Only request the HTTP header from the server without the actual web page.
Although this saves bandwidth because it transfers less data, we do not recommended that you use this. This is because the measured request time is not the one that your users experience and you might not be notified of slow results or timeouts.

Postdata

This setting is only visible if you select POST above. Enter the data part for the POST request.

No Extensible Markup Language (XML) is allowed here.

Require Keyword

Define if the sensor checks the result at the URL for keywords:

▪Do not check for keyword (default): Do not search for keywords in the result.

▪Set sensor to warning status if keyword is missing: Check if a keyword exists in the result. If it exists, set the sensor to the Warning status.

▪Set sensor to down status if keyword is missing: Check if a keyword exists in the result. If it exists, set the sensor to the Down status.

The content check is only intended for HTML websites and might not work with other target URLs.

Response Must Include

This setting is only visible if you select Set sensor to warning status if keyword is missing or Set sensor to down status if keyword is missing above. Define the search string that must be part of the result at the URL.

If the result at the URL does not include the search pattern, the sensor shows the status defined above and displays this string along with the affected URL in the sensor message.

Only simple text search is available here.

The characters * and ? work as placeholders. * stands for no number or any number of characters and ? stands for exactly one character. You cannot change this behavior. The literal search for these characters is not possible.

Exclude Keyword

Define if the sensor checks the result at the URL for keywords:

▪Do not check for keyword (default): Do not search for keywords in the result.

▪Set sensor to warning status if keyword is found: Check if a keyword exists in the result. If it exists, set the sensor to the Warning status.

▪Set sensor to down status if keyword is found: Check if a keyword exists in the result. If it exists, set the sensor to the Down status.

The content check is only intended for HTML websites and might not work with other target URLs.

Response Must Not Include

Define a string that must not be part of the result at the URL. If the data includes this string, the sensor shows the Down status and displays this string along with the affected URL in the sensor message. Enter a string.

Only simple text search is available here.

The characters * and ? work as placeholders. * stands for no number or any number of characters and ? stands for exactly one character. You cannot change this behavior. The literal search for these characters is not possible.

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.

You can set a different primary channel later by clicking 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.
You 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.

Downtime

In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status

Sum

The loading time of the complete transaction in milliseconds (msec)

This channel is the primary channel by default.

Time of URL [#]

The loading time of single URLs in msec