Summary
If you're using a Private Synthetic location, at some point, you'll want to check the logs for more information about what you're troubleshooting. Synthetic ActiveGates produce several logs that help diagnose issues with execution, scheduling, and communication in Synthetic Monitoring. This article summarises the most useful of these logs, where to find them, and what they contain.
Default locations for logs
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'll 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 doesn't 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 when the VUC service starts up and contains information such as the process ID and the port being used. It often contains useful information when the VUC service fails to start up or stops 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 detailed logging of the Browser Monitor module and includes visit lifecycle and execution messages. It contains information on screenshot storage, WebSocket issues, and other problems encountered during the startup of the Browser module and execution of Browser monitors. The outcome of the diagnostics test on startup can be found in this log by searching for DIAGNOSTICS TEST
vuc-browser.debug.log
This log provides debug-level details from the browser monitor diagnostics tests that are run when the Synthetic module starts up.
vuc-dns-execution.log
This log file details monitor execution events
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 startup can be found in this log by searching for DIAGNOSTICS TEST
vuc-http-custom.log
Entries in this log are generated from JavaScript execution. You'll find log messages created by the API calls api.info(message), api.warn(message), and api.error(message).
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.debug.log
This log provides debug-level details of the diagnostics tests run by the HTTP monitor when the Synthetic module starts up.
vuc-icmp-execution.log
This log file details monitor execution events
vuc-multi.log
This log provides high-level NAM, Multi-protocol, module logging, and covers the execution and lifecycle of visits
vuc-multi.debug.log
This log provides debug-level details of the NAM diagnostics tests run when the Synthetic module starts up.
vuc-tcp-execution.log
This log file details monitor execution events
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
Hourly archive zip files of execution logs from the logs folder are created 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).
What's Next
If you have any questions about the purpose of a synthetic log file, add a comment.
Related reading
📖Synthetic Troubleshooting Map
📖 Missing Synthetic screenshots. Information and how to troubleshoot...
📖 Why did the Synthetic Module on a Synthetic ActiveGate fail to update? Showing Failed or Skipped
📖 Why is my Synthetic ActiveGate shutting down?
