Consider the following scenario in Microsoft SQL Server 2016 or 2017:
- You set up SQL Server Managed Backups on one or more of your databases.
- 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.
The following factors may cause instability of a log backup:
- 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.
- 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.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.