Google appengine java.io.IOException: Server returned HTTP response code: 500 for URL

[sh4d0000]

Hello, I keep seeing this error in my google appengine app log and I can't figure out what is the issue

java.io.IOException: Server returned HTTP response code: 500 for URL: http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token

at com.google.devtools.cdbg.debuglets.java.GceMetadataQuery.readResponse

at com.google.devtools.cdbg.debuglets.java.GceMetadataQuery.queryMetadataAttribute

at com.google.devtools.cdbg.debuglets.java.GceMetadataQuery.lazyQueryAccessToken

at com.google.devtools.cdbg.debuglets.java.GceMetadataQuery.getAccessToken

at com.google.devtools.cdbg.debuglets.java.GcpHubClient.openConnection

at com.google.devtools.cdbg.debuglets.java.GcpHubClient.registerDebuggee

[christianpaula]

Hi @sh4d0000,

Welcome to Google Cloud Community!

This error typically indicates that there was an issue with the connection to the Google Cloud metadata server. The metadata server provides information about the instance of your App Engine application that is currently running, such as its service account and access token.

There could be a variety of reasons for the error. It could be due to a network issue, an issue with the metadata server, or a problem with the credentials being used to access the metadata server.

Here are a few steps you can try to troubleshoot the issue:

1. Check the network connectivity of your application. Make sure that your application is able to reach the metadata server at the URL specified in the error message. You can try accessing the URL in a web browser to see if it is reachable.
2. Check the credentials being used by your application to access the metadata server. Make sure that the service account has the necessary permissions to access the metadata server.
3. Check the logs of your App Engine application to see if there are any additional details about the error. This could help you identify the root cause of the issue.
4. If you are still unable to resolve the issue, you may want to consider reaching out to Google Cloud Support for further assistance. They may be able to provide more information about the cause of the error and help you resolve it.

You can find more information about the Google Cloud metadata server and its API in the official documentation:

• Google Cloud metadata server overview: https://cloud.google.com/compute/docs/storing-retrieving-metadata
• Google Cloud metadata server API reference: https://cloud.google.com/compute/docs/reference/rest/v1/projects.instanceTemplates

This documentation should provide more information about the metadata server, its API, and how to use it in your App Engine application. It should also contain details about the possible error codes that can be returned by the metadata server and how to handle them.

Thanks