Archive for June, 2018

Delete StatefulSet in Kubernetes fails with NotFound

I have created a stateful set with MongoDB databases in Kubernetes with AKS. In order to test the persistent volumes I tried to delete it, but to my surprise that failed:

Error from server (NotFound): the server could not find the requested resource

What? Getting the resource worked, but kubectl describe failed. What to do? I finally found out that my kubectl client was incompatible with the server. Apparently Kubernetes supports one version higher or lower, but kubectl is at 1.10 and the server at 1.8.

Categories: Kubernetes

Terminal in docker exec a mess

Fairly recently the terminal for docker exec has started to misbehave. When I enter a running Wildfly container to view the logs the output becomes garbled with less, vi and other tools. It appears the reason is that the terminal size is not detected (#33794). The solution on Linux/Mac is to pass in the size:

docker exec -e COLUMNS="`tput cols`" -e LINES="`tput lines`" -it imagename

Unfortunately that doesn’t work on Windows. The mode command can provide the columns, but not the number of lines, which must be hard-coded.

Categories: Docker

Azure SQL Server VM backup failures

SQL Server VMs in Azure can be backed up using the SQL Server configuration blade in the portal. When this has been enabled the logs can be swamped by errors similar to:

2018-06-04 11:44:59.88 Backup BACKUP failed to complete the command BACKUP LOG master. Check the backup application log for detailed messages.

Fear not, it is only temporary. A SQL Server backup consists of two parts: a full backup of the database(s) and transaction logs. When no full backup has been done the transaction log backups fail with the error above. The errors should go away when the first full backup has been completed successfully.

As a side note there is no “application log”, the message refers to the calling application and in this case that is the Azure SQL Server extension. It doesn’t log anything useful.

Categories: Database