Vunetrix Network Monitor vCloud

Vunetrix Manual: HTTP Full Web Page Sensor

The HTTP Full Web Page sensor monitors the full download time of a web page including assets such as images etc. In the background, it opens the web page in a browser instance to perform the measurement. Links are not followed. The sensor shows the loading time of the full page. Note: Be careful with this sensor, as it can generate considerable internet traffic if used with a low scanning interval!

Note: This sensor type can have a high impact on the performance of your monitoring system. Please use it with care! We recommend using not more than 50 sensors, on each probe, of this type of sensor.

Add Sensor

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

Sensor Settings

On the sensor's details page, click on the Settings tab to change settings.

Note: If not set explicitly in a sensor's settings, it will connect to the IP Address or DNS Name defined in the settings of the parent device the sensor is created on.

Basic Sensor Settings

Sensor Name

Enter a meaningful name to identify the sensor. The name will be shown by default in the device tree and in all alarms.

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 using 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. Those are not visible here.

Priority

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

Full Page Download Settings

Timeout (Sec.)

Enter a timeout in seconds for the HTTP request. If the reply takes longer than this value the request is aborted and an error message is triggered. The maximum value is 900 seconds (15 minutes).

URL

Please enter the URL the sensor will load. If you enter an absolute URL, this address will be independent from the IP address/DNS name setting of the device this sensor is created on. Vunetrix uses a smart URL replacement which allows you to use the parent device's IP address/DNS name setting as part of the URL. For more information, please see section Smart URL Replacement below.

Browser Engine

Define which browser will be used to load the web page. Choose between:

  • Chromium (recommended): Use the "WebKit" engine that is delivered with Vunetrix to perform the loading test. With each scanning interval, Vunetrix will load the URL defined above in an instance of "Chromium" and measure the time until the page is fully loaded. This is the recommended setting.
  • PhantomJS (Headless Webkit): Use the "PhantomJS" engine. This engine can have a high impact on your probe system's CPU and memory load, but there are additional options for result handling available (see below).
  • Internet Explorer: With each scanning interval, the URL defined above is loaded in the background in an instance of Internet Explorer. Vunetrix uses the Internet Explorer of the system running the Vunetrix probe. Note: For full functionality we strongly recommend installing Internet Explorer 8 or higher on the system running the Vunetrix probe. The probe machine is either the local system (on every node, if on a cluster probe), or the system running the remote probe on which the sensor is created on.

Note: For all browser engines, the same proxy settings are used that are configured for the Windows user account the Vunetrix probe is running on (this is usually the Windows local "system" user account, if not changed). Those settings are accessible via the Internet Explorer of this system. If you want to e.g. use a proxy for this full web page sensor test, please adjust the Internet Explorer's settings accordingly (on the computer running the probe; on all nodes, if in a cluster).

Security Context

Define the Windows user account that will be used to run the browser engine. Choose between:

  • Use security context of probe service (default): Run the browser engine under the same Windows user account the probe is running on. By default, this is the local 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 this sensor is created on. Please go to the sensor's parent device's settings to change the Windows credentials. Note: When using the Chromium browser engine above, this is the recommended setting here.

Result Handling

This setting is only visible if the PhantomJS engine is selected above. This browser engine can render and store screenshots of the loaded web page. Choose between:

  • Discard loaded web page (recommended): Do not store the requested web page.
  • Store latest screenshot of the web page: Render and store the last result of the web page to the "Logs (Sensors)" directory (on the remote system, when used on a remote probe; on the Master node, if in a cluster). This is for debugging purposes. The file will be overridden with each scanning interval. It will be named after the pattern "Fullpage of Sensor (ID).jpg". For information on how to find the folder used for storage, please see Data Storage section.
  • Store ongoing screenshots of the web page (use with caution!): Render and store one new screenshot of the web page with each sensor scan, and store the pictures in the "Screenshots (Fullpage Sensor)" directory (on the remote system, when used on a remote probe). For information on how to find the folder used for storage, please see Data Storage section. This option can be used to create a visual history of the web page. Note: Depending on the monitored website and the scanning interval of the sensor, a very high amount of data can be created! Use with care, and make sure you set appropriate data purging limits in the System Administration—Core & Probes settings.

Note: If necessary, you can change the window size of the rendered screenshots. See section More for details.

Authentication

This setting is only visible if the PhantomJS engine is selected above. Define if the monitored web page needs authentication for access. Choose between:

  • No authentication needed: Access to the web page is granted without authentication.
  • Web page needs authentication: Vunetrix will automatically try using HTTP Basic authentication (BA) or Windows NT LAN Manager (NTLM) to access the web page with authentication. Enter the credentials below. Note: The option basic access authentication will forward the credentials in plain text!

User

This setting is only visible if the PhantomJS engine with authentication is selected above. Enter the user name for the web page.

Password

This setting is only visible if the PhantomJS engine with authentication is selected above. Enter the password for the web page.

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 for this object, disable inheritance by clicking on the check mark symbol in front of the respective setting name. You will then see the options described below.

Scanning Interval

Scanning Interval

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

Schedules, Dependencies, and Maintenance Window

Note: Inheritance for schedules, dependencies, and maintenance windows cannot be interrupted; the according settings from the parent objects will always be active. However, you can define additional settings here. They will be active in parallel to 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.

Maintenance Window

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

  • Not set (monitor continuously): No maintenance window will be set.
  • Set up a one-time maintenance window: Pause monitoring within a maintenance window.

Maintenance Begins At

This field is only visible if maintenance window is enabled 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 maintenance window is enabled 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 it is created on is in a Down status, or if it is paused by another dependency.
  • Select object: Pause the current sensor if the device it is created on is in an Down status, or if it 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 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.

Dependency

This field is only visible if the select object option is enabled above. Click on the reading-glass symbol and use the object selector to choose an object on which the current sensor will be dependent on.

Delay (Seconds)

Define a time span. After the master object for this dependency comes back to an Up status, monitoring of the depending objects will be additionally delayed by the defined time span. This can help 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 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 right 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 settings of the parent object.
  • None: Users in this group cannot see or edit the object. The object does not show up in lists and 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 about access rights, please see section User Access Rights.

Smart URL Replacement

Instead of entering a complete address in the URL field of an HTTP sensor, you can merely enter the protocol followed by colon and three slashes (that means you can enter either http:/// or https:/// or even a simple slash / as equivalent for http:///). Vunetrix will then fill in the parent device's IP address or DNS name in front of the third slash automatically. Whether this results in a valid URL or not, depends on the IP address or DNS name of the device where this HTTP sensor is created on. In combination with cloning devices, the smart URL replacement makes it easy to create many like devices.

For example, if you create a device with DNS name www.example.com and you put an HTTP sensor on it, you can provide values the following ways:

  • Providing the value https:/// in the URL field, Vunetrix will automatically create the URL https://www.example.com/ from that.
  • Using the value /help in the URL field, Vunetrix will automatically create and monitor the URL http://www.example.com/help
  • It is also possible to provide a port number in the URL field which will be taken over by the device's DNS name and internally added, for example, http://:8080/

Note: Smart URL replacement does not work for sensors running on the "Probe Device".

Edit Sensor Channels

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

Notifications

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

Others

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

Sensor Settings Overview

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

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