How to enable dtHealthCheck

[HannahM]

• Summary
• What is dtHealthCheck?
• How to enabledtHealthCheck
• Step 1: Open Chrome or Edge Developer Tools
• Step 2: AccessNetwork Conditions
• Step 3: Add a custom User Agent
• Step 4: Open the webpage and record the HAR file
• Step 5: Export the HAR File
• What's Next

Summary

When investigating injection issues, it can be helpful to enable dtHealthCheck to gather diagnostic information. This article provides more information on this and how to enable this feature.

What is dtHealthCheck?

dtHealthCheck is a OneAgent diagnostic feature, enabled by adding the User-Agent header value dtHealthCheck. The OneAgent technologies supporting Real User Monitoring add headers to the responses of any requests made with this User-Agent, and sometimes an HTML marker is included in the body. If automatic injection problems occur, these headers provide diagnostic details, which may help identify the issue.

The following instructions guide you through capturing diagnostic data with dtHealthCheck using Google Chrome or Microsoft Edge.

How to enable dtHealthCheck

Step 1: Open Chrome or Edge Developer Tools

Open Developer Tools using one of the options below:

• Open the Browser and press F12 on your keyboard, or
• Right-click anywhere on the page and select "Inspect" or "Inspect Element", or
• On Chrome, you can also use the three-dot menu in the top-right corner of the browser > More tools > Developer tools.
  
  

Step 2: Access Network Conditions 

Open Network Conditions using one of the options below:

1. Using the Network tab
   1. Click on the "Network" tab in the Developer Tools menu bar.
   2. In the additional settings bar, select the "More network conditions..." icon , and the Network conditions pane will open.
      
      or
2. Using the More Tools menu 
   1. In the Developer Tools pane, locate and select the three vertical dots (Options) in the top-right corner of the pane.
   2. Click on the "More Tools" option.
   3. Click on  "Network conditions".
      

Step 3: Add a custom User Agent

1. In the "Network conditions" pane > User agent section, Untick the "Use browser default" checkbox
2. In the dropdown box, select "Custom..."
3. Enter "dtHealthCheck" into the text field.
   

Step 4: Open the webpage and record the HAR file

In the same tab that you have set the User-Agent to "dtHealthCheck" in the "Network Conditions" settings, open or reload the webpage and create the session.

Note: the actions must be completed in the same tab as the Network Conditions setting is made, as otherwise the option will be reset to the default.

It can be confirmed that the dtHealthCheck User Agent has been applied by checking for it in the response headers of resources.

For further information on creating HAR files, see How to generate a HAR file.

Step 5: Export the HAR File

Export the HAR file as described in How to generate a HAR file.

What's Next

If you've been asked to provide the HAR file to support, then please do that. You can also find futher troubleshooting in Troubleshooting automatic RUM injection failures and more generally for RUM here.

If you've completed troubleshooting steps but still can't identify the root cause of your issue and resolve it, please contact Dynatrace via the in-product chat or by creating a support ticket.

To help our support team investigate efficiently, include the following information:

• Access details, if the page is publicly available, and you can grant access to the support team.
• If access can't be granted: A HAR file, or, preferably, a Fiddler session capturing the whole scenario—ideally with dtHealthCheck enabled, as described above.
• A summary of the troubleshooting steps you've completed.

Providing this information upfront will help speed up the resolution process.

[AntonPineiro]

Thank you!