Public preview: Rolling Upgrades with MaxSurge for Virtual Machine Scale Sets
Published date: 17 May, 2023
Rolling Upgrades with MaxSurge is designed to create new VMs with the latest scale set model to replace the VMs running with the previous model. Rolling Upgrades with MaxSurge replaces VMs with new instances rather than taking existing VMs in a scale set offline for upgrades.
As part of the Rolling Upgrade model, the MaxSurge flag signals Azure to:
- Create new VMs with the latest scale set model
- Verifies the new VMs are healthy
- Move the VMs into the scale set
- Remove the old VMs from the scale set
- Mark the old VMs for deletion
This continues in batches until all VMs in the scale set are up to date with the latest scale set model.
Rolling Upgrades with MaxSurge is especially helpful because the instances in your Scale Set can continue to receive traffic while new instances are being upgraded to the latest model rather than taking existing instances offline for upgrades.