on - edited on by
HannahM
- Synthetic Screenshots
- Screenshot Storage
- S3
- Cluster
- Troubleshooting
- Private Locations
- Upload Errors
- Helpful Links
- What's Next?
Synthetic Screenshots
- Reference (expected/ success) screenshots are taken when the monitor is created or edited, and subsequently, every 24 hours from a random monitoring location. So, if a monitor is executed on several locations, the success screenshot shown for all locations will be the same screenshot, from the one random location.
- Screenshot retention is based on execution retention. They are considered part of the execution data for the execution when they were taken. The default retention time for screenshots is 35 days, however, it can be less in some Managed Environments depending on their storage settings.
- If your Synthetic monitor has never been successful or has not been successful in the last 35 days, you will not have any "expected" screenshots.
- Screenshots are captured at the end of each script event, even those without timings.
- Success (expected) screenshots are only taken a successful first execution, never on a retry. So if your monitor is always successful and has no screenshots, it is likely that all executions are Execution type: re-run
- You can verify the origin of a screenshot by following these steps:
- Navigate to the Synthetic dashboard and click on "Analyze executions."
- Select the specific execution you're interested in from the list.
- Above the screenshot, you will find a label displaying the date and location, indicating, "Screenshot from <date> in <location>."
- Click on this link, and you will be instantly directed to the execution where the screenshot was taken or attempted to be taken. Example:
Screenshot Storage
- SaaS: Screenshots are stored in Amazon S3.
- Managed: Clusters installed after version 1.216 store screenshots on the cluster, in Cassandra. For clusters installed before this version, screenshots are stored in Amazon S3. To modify the storage setup to cluster-based, create a support ticket.
S3
For screenshots stored in Amazon S3, the following domains in the firewall configuration must be allowed:
- ruxit-synth-screencap.s3-accelerate.amazonaws.com for screenshot storage.
- ruxit-synth-screencap.s3.amazonaws.com for screenshot access and viewing.
Cluster
For screenshots stored in Cassandra, on a Managed Cluster, make sure the endpoint below is allowed to receive data on your Cluster ActiveGate (only required if you are using Public locations)
- /beacon/synthetic/screenshot/[uuid] - Where uuid is the Environment ID.
- you may also wish to allow public location IP addresses on any network devices that may prevent access to the Cluster ActiveGate endpoint or modify the data in any way.
Troubleshooting
- Confirm that the executions are not always re-runs. Go to the Synthetic, click on “Analyze executions”, and in the execution time, select different timings and confirm the “Execution type” is standard (and not re-run) for some of the executions.
- For SaaS, or Managed that stores screenshots on S3, ensure that the ActiveGate can access the Amazon S3 service.
- For Managed, that stores screenshots in Cassandra on the cluster, ensure that the Cluster ActiveGate url is publicly available, allowing Public location IPs in any Firewalls etc.
Private Locations
How to identify issues in the logs:
- In the browser_#.log file (/var/tmp/dynatrace/synthetic or %PROGRAMDATA%\dynatrace\synthetic):
Look for any errors related to "SCREENSHOT" or "SCREENCAP." These errors are related to taking and storing the screenshots locally on the Virtual User Controller (VUC).
- In the vuc-browser.log file. (/var/log/dynatrace/synthetic/ or <LOG>/synthetic/log or %PROGRAMDATA%\dynatrace\synthetic\log):
Check for "[SCREENCAP]" errors. These errors occur when uploading the images from the VUC to either S3 or the cluster.
Upload Errors
Status Code: 403
These messages can be seen in the vuc-browser.log file.
ERROR AwsS3CloudFileManager: [SCREENCAP] Exception caught while uploading file /var/tmp/dynatrace/synthetic/screenshots/ AmazonS3Exception: Forbidden (Service: Amazon S3; Status Code: 403; Error Code: 403 Forbidden…)
ERROR AwsS3CloudFileManager: [SCREENCAP] Exception caught while uploading file /var/tmp/dynatrace/synthetic/screenshots/image.jpeg AmazonS3Exception: URLBlockedServers (Service: Amazon S3; Status Code: 403; Error Code: 403 URLBlockedServers)
Confirm what configuration is needed for the private location to reach s3.
- Proxy needed
Add the proxy connection details to the [synthetic] section of the ActiveGate custom.properties file (which are located in the ActiveGate configuration directory)
Example:[synthetic] proxy-server=<proxy between AG and S3> proxy-port=8080 proxy-user=username proxy-password=password - Proxy not needed
Add "proxy-non-proxy-hosts" to specify a list of hosts that require communication without proxy.
More information: https://www.dynatrace.com/support/help/shortlink/synthetic-proxy-authentication - Proxy only needed for either S3 or Monitor
If the proxy should be enabled for S3 but not for Monitors, or vice versa, then you can selectively enable proxy for Monitors or S3.
Set up the proxy settings in custom.properties as usual. Then adding following flags to VUC user.properties (default path /var/lib/dynatrace/synthetic/config/user.properties- to enable the proxy for monitors and disable it for s3
com.vuc.proxy.s3.enabled=false com.vuc.proxy.monitor.enabled=true - to disable the proxy for monitors and enable it for s3
com.vuc.proxy.s3.enabled=true com.vuc.proxy.monitor.enabled=false
- to enable the proxy for monitors and disable it for s3
Restart vuc.service/ Dynatrace Synthetic service after any changes to the proxy settings.
Unable to find valid certification path to requested target
These messages can be seen in the vuc-browser.log file.
ERROR AwsS3CloudFileManager: [SCREENCAP] Exception caught while uploading file /var/tmp/dynatrace/synthetic/screenshots/ SunCertPathBuilderException: unable to find valid certification path to requested target.
This usually means that there is a certificate issue when ActiveGate is trying to connect to S3.
- Add the certificate to truststore. Here you can find the documentation with more information.
407 Proxy Authentication Required
These messages can be seen in the vuc-browser.log file.
ERROR AwsS3CloudFileManager: [SCREENCAP] Exception caught while uploading file C:\\ProgramData\\dynatrace\\synthetic\\temp\\synthetic\\screenshots\\image.jpeg to S3 bucket... Proxy Authentication Required (Service: Amazon S3; Status Code: 407; Error Code: 407 Proxy Authentication Required; Request ID: null; S3 Extended Request ID: null; Proxy: <yourproxy>)
Proxy credentials are needed.
- Add the proxy username and password details to the section of the custom.properties file, in /var/lib/dynatrace/gateway/config or %PROGRAMDATA%\dynatrace\gateway\config, which contains the proxy connection information, most likely [synthetic].
proxy-user=username proxy-password=passwordAfter saving it, the proxy password will be encrypted. You can then restart the Dynatrace Gateway and Dynatrace Synthetic services on Windows or vuc and dynatracegateway services on Linux.
Helpful Links
Set up a proxy for private synthetic monitoring
Synthetic details for browser monitors
Useful Synthetic ActiveGate logs
What's Next?
If the screenshots are still missing, or unexplained, after following the troubleshooting, please create a Support ticket and provide the following:
- Link to any monitors/ monitor executions that are missing screenshots
- Support Archive for the ActiveGate machine, if access to the ActiveGate is not available to Support
- Explanation of troubleshooting steps taken and the results
