How will the Service Fabric 9 Third Refresh enforced Silver/Gold Durability requirement work? Can it be disabled?

Question

In the announcement for Service Fabric 9 Third Refresh you state:

Azure Service Fabric will block deployments that do not meet Silver or Gold durability requirements starting on 9/30/2022. 5 VMs or more will be enforced with this change to help avoid data loss from VM-level infrastructure requests for production workloads. Enforcement for existing clusters will be rolled out in the coming months.

Can you please clarify what is meant by "deployments" here? Will application deployments/upgrades fail? Or does this refer to ARM deployments for a Service Fabric cluster (which would then assumedly fail if the ARM template was updating or deploying a cluster with a durability of Bronze and VMSS with less than 5 nodes)?

Is there any way to disable this requirement? It seems this would mean it was impossible to deploy a Bronze durability cluster.

We have various non-production clusters that we run on Bronze Durability with multiple (minimum) 3 node VM ScaleSets. We also have some stateless Production services that run on Service Fabric clusters with Bronze Durability and a single 3 node VM ScaleSet. Does the above mean that we are not going to be able to deploy (or update via ARM) these clusters once this requirement is enforced without also moving them to Silver Durability?

The cost implication here for us will be fairly significant as we have a lot of small 3 node clusters that it seems we'd have to add 2 nodes to in order to continue to update/maintain.

Answer 1

Hi Mark, couple of clarifications:

1. This does not impact the VMSS with Bronze durability at all. The VM Count requirement is not changing for durability Bronze.
2. This is only applicable to the VMSS with Silver & Gold durability.
3. Initially, we will only enforce these on the new clusters created post 10/30 and gradually we will enable these checks on all clusters
4. When enabled for all existing clusters, these checks will prevent VMSS update operations (like Scale-in, Reimage operations etc..), if the VMSS is found to be misconfigured. It will not impact application updates.
5. We want customers to understand that these misconfigurations, even though the requirements were publicly documented since the beginning but never enforced until now, should be avoided as they can result in unreliability or even availability losses.

Answer 2

The change does not impact Bronze clusters. It seems previously despite the requirement for Silver and Gold durability clusters being a minimum of 5 nodes, this wasn't actually enforced as part of deployment. The change in SF9 Refresh 3 is that the requirement will be enforced during deployment.

Microsoft provided the following clarification on the announcement blog:

The enforcement for 5 VMs or more and Windows updates disabled for VMSS with Silver or Gold Durability is postponed to 30 October 2022. Just to be clear:

The VM Count requirement is not changing for Bronze durability and is only applicable to the VMSS with Silver & Gold durability. This will be enforced only on the new clusters created after 10/30 and gradually we will enable these checks on all clusters. When the checks are enabled to the existing clusters in the future, this will prevent VMSS update operations (like Scale-in, Reimage operations etc..), if the VMSS is found to be misconfigured. It will not impact application updates.
We want customers to understand that these misconfigurations, even though the requirements were publicly documented since the beginning but never enforced until now, should be avoided as they can result in unreliability or even availability losses.

Further the announcement has been edited to include:

VM count requirement is not changing for Bronze durability.

The rollout of this requirement has also been delayed to the 30th October 2022.