Azure VMSS scale up time estimate?

Question

We have 21 machines in our VMSS in our Service Fabric production cluster. We decided to scale it up to more CPU/RAM.

How much time does it usually take? I need to set downtime maintenance window. I know that SF updates VMs by upgrade domains but we have stateful app that will be non functional during scale up.

Is it a thumb rule to estimate upgrade time?

Answer 1

Hello ole9us,

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that you would need information and clarity to:

Scale up your VMSS in Service Fabric production cluster

Scaling up the VM instances in a Service Fabric cluster involves a few steps that can vary in duration depending on several factors. Since you have stateful applications and are concerned about downtime, these are factors affecting Scale-Up Time:

• Size of VMs
• Number of VMs
• Service Fabric Upgrade Domains
• Stateful Services

Also, would like to know the time it takes so that you can plan for downtime maintenance window

About the time, if provisioning a new VM takes around 10 minutes and you have 21 VMs, the total provisioning time could be around 210 minutes (3.5 hours) in a worst-case scenario.

• An upgrade domain might take around 10-30 minutes to complete, depending on the load and statefulness of your applications.
• After scaling up, you should account for additional time to test and validate that the new configuration is working as expected. This might take additional time based on the complexity of your services.

To know if it's a thumb rule to estimate upgrade time.

If you're interested in a good rule of thumb to estimate the total time by considering the provisioning time, upgrade domain processing time, and any additional buffer for testing. The rough calculation should be based on:

VM Provisioning: 10 minutes per VM * 21 VMs = 210 minutes (3.5 hours)

Service Fabric Upgrade: Assuming 3-4 upgrade domains, and each takes around 30 minutes = 1.5 to 2 hours

Testing and Validation: 30 minutes to 1 hour

So, total Estimated Time will be around 5-7 hours.

I hope this is helpful! Do not hesitate to let me know if you have any other questions.

** Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful ** so that others in the community facing similar issues can easily find the solution.

Best Regards,

Sina Salam