Today we had an issue with Azure VMs where one VM in availability set of 2 just stopped responding. After few mins we noticed that machine was shutdown and the other VM in the set wasn't turned on (which should be ok as this isn't a failover). We have take a look at the VM monitoring and there wasn't a single log telling us that there was any downtime. The only thing that we found is 2 strange logs in the Management Services - Operation Logs.
- 11/12/2013 10:12:02 PM AutoscaleAction Succeeded VirtualMachinesAvailabilitySet:xyz Autoscale
- 11/12/2013 9:36:56 PM AutoscaleAction Succeeded VirtualMachinesAvailabilitySet:xyz Autoscale
The first one was with following details:
Description: The autoscale engine attempting to scale resource 'xyz' from 0 instances count to 1 instances count.
LastScaleActionTime: 20131106T173020Z
NewInstancesCount: 1
OldInstancesCount: 0
Second one:
The autoscale engine attempting to scale resource 'xyz' from 2 instances count to 1 instances count.
LastScaleActionTime: 20131112T203656Z
NewInstancesCount: 1
OldInstancesCount: 2
Does anyone know what may had happen ?
UPDATE
Azure Support has provided me with the feedback and they explained that machines were down due to host update.
Regards