Useful Synthetic ActiveGate logs

[HannahM]

Self Service Summary

If you are using a Private Synthetic location you will, at some point, want to check the logs for more information about what you are troubleshooting. This article aims to give you some direction on which logs to look at. 

Default locations for logs

• For Linux AGs
• For Windows AGs

You can also download the Support Archive from the WebUI by running the Dynatrace ActiveGate Diagnostics. This will only give you up to 7 days of Synthetic logs, so if you need a log that was last written before that you will need to find the file directly. 

Helpful files and folders

Synthetic installation log

• Linux: /var/log/dynatrace/synthetic/dynatracesynthetic-install_<datetimeOfInstall>.log
  If this file does not exist, you can check /tmp/ for any dynatracesynthetic-install <datetimeOfInstall>.log files.
  
• Windows: C:\ProgramData\dynatrace\autoupdater\log\Synthetic_<version>.log

The Synthetic installation log details the installation of the Synthetic module. This is the place to check if you see the Synthetic module update has failed or been skipped. It also provides information on the Chromium autoupdate.

It should be read alongside the Gateway installation log, which is located at:  

• Linux: /var/log/dynatrace/gateway/dynatracegateway-install_<datetime>.log
• Windows: C:\ProgramData\dynatrace\gateway\log\dynatrace_ag_install_<datetime>.log

 

Synthetic Module start up log (VUC Wrapper Launcher)

• Linux: /var/log/dynatrace/synthetic/VucwrapperLauncher_<datetimeOfLaunch>.log
• Windows: C:\ProgramData\dynatrace\synthetic\log\VucwrapperLauncher_<datetimeOfLaunch>.log

This log is written to when the VUC service is starting up and contains things like the process id and port being used. It often has helpful messages when the VUC service is failing during startup or has stopped unexpectedly.

 

Synthetic Module (VUC) Logs 

• Linux: /var/log/dynatrace/synthetic
• Windows: C:\ProgramData\dynatrace\synthetic\log\synthetic

vuc.log
This file captures the core VUC functionality logs. It includes logs related to the VUC's connection with the ActiveGate (e.g., localhost:9999/...), as well as startup/shutdown activities, common services, and the loading of configuration properties.

vuc-browser.log 

This log provides high-level Browser Monitor module logging and covers the execution and lifecycle of visits. It contains information on screenshot storage, WebSocket issues, and other problems encountered during the start up of the Browser module and execution of Browser monitors. The outcome of the diagnostics test on start up can be found in this log by searching for DIAGNOSTICS TEST

vuc-http-execution.log

This log file details monitor execution events, including script execution failures, SSL communication errors, DNS query timeouts, and other unexpected errors.

vuc-http-custom.log

Entries in this log are generated from JavaScript execution. You may find log messages created by the API calls api.info(message), api.warn(message), and api.error(message). 

vuc-http.log

This provides high-level HTTP Module logging, including monitor start and stop times, script loading, and detailed error information, such as "Unknown Method Error" and "Unexpected Error". The outcome of the diagnostics test on start up can be found in this log by searching for DIAGNOSTICS TEST

vuc-status.log

This log offers a summary of each VUC startup, including configuration settings and version information.

 

Synthetic Player (VUP) Logs

Location for individual Browser Monitor execution logs:

• Linux: /var/tmp/dynatrace/synthetic/logs
• Windows: C:\ProgramData\dynatrace\synthetic\temp\synthetic\logs

For archived logs:

• Linux: /var/tmp/dynatrace/synthetic/archivedLogs
• Windows: C:\ProgramData\dynatrace\synthetic\temp\synthetic\archivedLogs

Log File Format: <tenant_id>-<test_def_id>-<visit_id>-<timestamp>-ch.log

Execution logs from logs folder are archived hourly into 1 hour zip files in the archivedLogs folder.

These logs provide details on:

• WebSocket connections to the VUC.
• VUP, browser, and JavaScript Agent versions.
• Execution error codes and messages.
• Custom log entries created by API calls (e.g., api.info).