When you use the URL option to back up your SQL Server databases or transaction logs to Azure storage, the backup operations intermittently fail. Additionally, you receive an error message that resembles the following:
Msg 3202, Level 16, State 1, Server server_name, Line LineNumber
Write on "https://storage_account_name.blob.core.windows.net/container_name/file_name" failed: Backup to URL received an exception from the remote endpoint. Exception Message: The client could not finish the operation within specified timeout.
- This problem affects only backups to Azure storage if you use Azure Page Blobs or if you specify the WITH CREDENTIAL option in your backup statements, as in the following example query:
BACKUP DATABASE AdventureWorks2016 TO URL = 'https://my_storage_account_name.blob.core.windows.net/my_container_name/AdventureWorks2016.bak' WITH CREDENTIAL = 'my_credential_name' ,COMPRESSION ,STATS = 5; GO
- Backups to Azure storage that use Azure Block Blobs are not affected by this problem.
When you back up your databases to Azure Page Blobs by using BackuptoURL statements, SQL server internally calls a stand-alone application that is named BackuptoURL.exe. This problem occurs because the BackuptoURL application does not correctly handle transient failures. These failures can occur when the storage system rebalances on the back-end to handle spikes in data transfers that occur during backups.
Cumulative Update Information
This issue is fixed in the following cumulative updates for SQL Server:
This problem is fixed in the following on-demand hotfixes.
For SQL Server 2016 Service Pack 2 Cumulative Update 2
- After you apply this hotfix, the SQL Server version is 13.0.5206.0.
- This hotfix is also included in Cumulative Update 3 for SQL Server 2016 Service Pack 2
For SQL Server 2014 Service Pack 2 Cumulative Update 13
Note After you apply this hotfix, the SQL Server version is 12.0.5596.0.
SQL Server 2017
An on-demand hotfix is not yet released for SQL Server 2017. We will release an update as soon as a fix for this problem is available for SQL Server 2017.
SQL Server 2012
We recommend that you consider upgrading to the latest SQL Server version to take advantage of new features and fixes.
An on-demand hotfix will not be released for SQL Server 2012 because this product is out of mainstream support. For SQL Server 2012, you should either manually retry the failed backup operation or rely on the next iteration of the backup job to succeed. Or, you can write backups to either a local share, a network share, or a file share on another virtual machine (VM).
For information about how to download Microsoft support files, see the following article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.