Troubleshooting External Functions for GCP

This topic provides troubleshooting information for external functions for GCP.

In this Topic:

Platform-independent Runtime Issues

Data Type Return Values Do Not Match Expected Return Values

When passing arguments to or from an external function, ensure that the data types are appropriate. If the value sent can’t fit into the data type being received, the value might be truncated or corrupted in some other way.

For more details, see Ensure that Arguments to the External Function Correspond to Arguments Parsed By the Remote Service.

Error: Row numbers out of order

Possible Causes

The row numbers you return within each batch should be monotonically ascending integers starting at 0. The input row numbers must also follow this rule, and each output row should match the corresponding input row. For example, the output in output row 0 should correspond to the input in input row 0.

Possible Solutions

Ensure that the row numbers you return are the same as the row numbers you received, and that each output value uses the row number of the corresponding input. If this doesn’t work, then the input row numbers may not be correct or you did not return the rows in the correct order.

Next, ensure that the output row numbers start from 0, increase by 1, and are in order.

For more information about data input and output formats, see Remote Service Input and Output Data Formats.

Error: “Error parsing JSON: Invalid response”

Possible Causes

The most likely cause is that the JSON returned by the remote service (e.g. AWS Lambda function) is not constructed correctly.

Possible Solutions

Ensure that the external function returns an array of arrays, with one inner array returned for each input row received. Review the description of the output format at Data Format Received by Snowflake.

Error: Format of the returned value is not JSON

Possible Causes

Your return value includes double quotes inside the value.

Possible Solutions

Although JSON strings are delimited by double quotes, the string itself should not start and end with a quotation mark in most cases. If the embedded double quotes are incorrect, remove them.

Error: Function received the wrong number of rows

Possible Causes

The remote service tried to return more or fewer rows than it received. Even though the function is nominally scalar, it might receive multiple rows in the body field of the event parameter, and should return exactly as many rows as it received.

Possible Solution(s)

Ensure that the remote service returns one row for each row that it receives.

GCP-specific Issues

Error: Request fails with ‘{“message”:”Audiences in Jwt are not allowed”,”code”:403}’

Possible Causes

The value in the API integration’s google_audience field is not allowed.

Possible Solutions
  • Verify that the API Integration’s google_audience value matches the managed service name of your API, which should be recorded in the “Managed Service Identifier” field in your tracking worksheet.

  • If you added an x-google-audiences field to the securityDefinitions section of your API config file, make sure that the value in x-google-audiences matches the value in the google_audience field of the API integration.

For more information about authenticating with Google, see the Google service account authentication documentation.

Error: Request fails with ‘{“message”:”Jwt is missing”,”code”:401}’

Possible Causes
  • The value of the x-google-issuer field in the securityDefinitions field in the configuration file might not match the value of the API_GCP_SERVICE_ACCOUNT for the API integration, as recorded in your tracking worksheet.

  • The value in x-google-issuer might contain extra whitespace.

Possible Solutions
  • Update the x-google-issuer to match the API_GCP_SERVICE_ACCOUNT.

  • Remove unneeded whitespace.

Error: Request fails with ‘403 Forbidden’

Possible Causes

The service account using the config does not have the appropriate permissions on the backend.

Possible Solutions

Update the service account’s permissions.