[HADOOP-14582] WASB exception handling to translate specific failures into specific exceptions

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.8.1
• Component/s: fs/azure
• Assignee: Unassigned
• Reporter: Steve Loughran
• Created: 23/Jun/17 17:08
• Updated: 19/Dec/17 16:55

Description

Mucht of the exception handling logic in WASB is a catch-and-wrap-as-IOE handler.

    } catch (Exception e) {
      // Re-throw the exception as an Azure storage exception.
      throw new AzureException(e);
    }

This works, but

1. it doesn't offer much in the way of diagnostics
2. There's no way to make sense of the failure
3. It catches and wraps IOEs, which don't need wrapping
4. It can double wrap IOEs around storage exceptions. Example PageBlobInputStream constructor wraps StorageException with IOE; if raised in AzureNativeFileSystemStore.retrieve() it will be caught and wrapped again.

Proposed: something akin to where S3A's translateException is going:

• take an incoming StorageException and based on its errorcode, choose whether or not to wrap in a specific java exception (FNFE, access denied, ...).
• AzureException to make it easy to get at the details
• Include operation & path in error text