Why is my Synthetic ActiveGate shutting down?

[HannahM]

• Self Service Summary
• Chromium
• Old version of Chromium
• Chromium version shows as80.0.0000.00
• Activegate and Synthetic Module mismatch
• Log Messages
• Windows Machines
• Contact Chat

 

Self Service Summary

Troubleshooting steps for when a Synthetic-enabled ActiveGate is running but the Synthetic Engine Status is showing as shutting down. Seen in Deployment Status> ActiveGates

Chromium

Old version of Chromium

The most common cause of this behaviour is an old version of Chromium. Dynatrace supports Chromium versions that are no more than two versions behind the latest Dynatrace-supported version for a specific ActiveGate release. Chromium can be manually updated using the instructions here.

Chromium version shows as 80.0.0000.00

If Chromium version shows as 80.0.0000.00 then the Synthetic Module in unable to recognise the version, so an update of Chromium version will also be required.

1. For Ubuntu machines using snap, follow these steps to uninstall and reinstall Chromium (replace the package with the expected version from here)

   sudo snap remove chromium 
   curl --remote-name https://synthetic-packages.s3.amazonaws.com/Chromium/snap/chromium-127.0.6533.88-2923.tgz 
   tar xzf chromium-127.0.6533.88-2923.tgz 
   sudo snap ack chromium.assert 
   sudo chown -R root:root /tmp/snap-private-tmp 
   sudo snap install --devmode chromium.snap 
   sudo chown -R dtuserag:dtuserag /tmp/snap-private-tmp 
   sudo systemctl restart vuc.service (or better restart whole machine)
   

2. If SELinux is enabled, reinstall Chromium with the permissive setting.

Activegate and Synthetic Module mismatch

Check if the Synthetic and ActiveGate major versions match. In the image above they do not. 

If the major versions are different, check this article  for why the Synthetic module failed to update. 

Log Messages

Download the logs from the ActiveGate using the ActiveGate diagnostics feature, otherwise you will need to check on the machine itself.  /var/log/dynatrace/synthetic or %PROGRAMDATA%\dynatrace\synthetic\log  

Check the vuc-status.log for DiagnosticResultsHolder and check if any modules failed to be operational. There are 4 to check multi-protocol, http, httpScript and browser.
Where the module start up is successful, you will see isOperational=true, e.g.

2024-09-18T01:10:53,190Z [DiagnosticResultsHolder]
 browser = `DiagnosticResultsChangedEvent[moduleName=BROWSER, diagnosticCasesResult=DiagnosticCasesResult[isOperational=true, cases={BROWSER_MAIN=DiagnosticCaseDetail[isAvailable=true], BROWSER_FALLBACK=DiagnosticCaseDetail[isAvailable=true]}]]`

And where the module startup is not successful, you will see isOperational=false, e.g.

2024-09-23T07:40:25,237Z [DiagnosticResultsHolder]
    browser = `DiagnosticResultsChangedEvent[moduleName=BROWSER, diagnosticCasesResult=DiagnosticCasesResult[isOperational=false, cases={BROWSER_MAIN=DiagnosticCaseDetail[isAvailable=false]}]]`

Depending on which modules were unable to startup, check the relevant logs for ERRORs and WARNINGS

1. for HTTP Monitors, vuc-http.log, vuc-http.debug.log and additional log files with stdout/stderr output in executors subdirectory

2. for Browser Monitors, vuc-browser.log & vuc-browser.debug.log

   1. If you see Running as root without --no-sandbox is not supported.then the issue is likely related to the user running the Synthetic Engine. This should be run by dtuserag and not root. Reinstalling the ActiveGate will correct this behaviour.

3. for NAM monitors, vuc-multi.log, vuc-multi.debug.log
   
   

Windows Machines

1. check the OS is supported. For instance, we do not support Windows 2012 (R2) and from 1.263 found that this causes the VUC to show this shutting down status. This is due to Google stopping support for Chrome on Windows 2012 (R2) with Chrome 109. https://support.google.com/chrome/a/answer/7100626?hl=en

2. Check if there have been any recent Windows updates, like this one that prevented Chrome from starting up. 
3. Check if the Activegate machine has any anti-virus/ anti-malware installed. If it does, reboot the machine.
   As outlined in our documentation, Synthetic-enabled ActiveGates on Windows hosts are not supported with any anti-virus or anti-malware software installed, as this may cause conflicts with the Dynatrace software, leading to issues such as this.  

Contact Chat

If none of the previous steps resolved the issue, then open a chat and provide the Support Archive from the ActiveGate the troubleshooting steps you have already completed.

You can find further troubleshooting tips for Synthetic in the Synthetic Troubleshooting Map