Troubleshooting¶

Alation Cloud Service Applies to Alation Cloud Service instances of Alation

Customer Managed Applies to customer-managed instances of Alation

For information about logs, refer to Troubleshooting.

Refer to the following scenarios for help in troubleshooting common issues.

Column Extraction Failure¶

Problem¶

In some cases, the Azure Blob OCF connector fails to extract column metadata, even with a successful Test Connection and Metadata Extraction (MDE).

Symptoms¶

Column extraction fails with following error in the Extraction History:
```
accessKey is not a valid Base64 string
```
Test Connection and MDE are successful.

Cause¶

Incorrect Access Key format. The Access Key may contain:

Leading or trailing spaces
Invisible characters such as zero-width space (u200B) or a Unicode whitespace
Introduction of non-printable or non-ASCII characters during copy-paste operation
Line breaks or encoded formatting from password managers, browsers, or word processors

The CData driver does not support the above characters in the key during column extraction. However, the Azure Blob SDK, used for Test Connection and Metadata Extraction (MDE), does allow these characters in a key. This can result in a successful test connection and MDE, even though the key will subsequently cause errors when the CData driver attempts column extraction.

Solution¶

Format the Access Key:
- Paste the key to a plain-text editor of your choice.
- Remove all:
  - Leading or trailing spaces
  - Line breaks
  - Invisible or non-printable characters
Provide the newly formatted key in the Access Key/Shared Access Signature field under the General Settings tab.
Save and click Schema Extraction under Metadata Extraction tab to run column extraction.