Symptoms
Consider the following scenario in Microsoft SQL Server 2016 or 2017:
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You set up SQL Server Managed Backups on one or more of your databases.
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You set a job schedule to run a log backup every n minutes or hours. For example, you schedule to run log backup every 5 minutes.
In this scenario, you may find the log backup does not occur as scheduled, and the Extended event shows the following information:
timestamp (utc) summary
date time +00:00 [SSMBackup2WADebugXevent] Database Name = database_name, Database ID = database_ID, Additional Info = SSMBackup2WA not scheduling log backup because none of the conditions matched.
Cause
The following factors may cause instability of a log backup:
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It takes a long time to finish the log backup. For example, you schedule a log backup to run every 6 hours, but it actually takes around 11 hours for the backup process to finish.
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There is a very large change to the log backup frequency. For example, you change the scheduled log backup from every 5 minutes to every 6 hours.
Resolution
This fix is included in the following cumulative updates for SQL Server:
Cumulative Update 1 for SQL Server 2017
Cumulative Update 5 for SQL Server 2016 Service Pack 1
About SQL Server builds
Each new build for SQL Server contains all the hotfixes and all the security fixes that were included with the previous build. We recommend that you install the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.
