MSSQL Database schema impact of running OS 11 and OS10 concurrently on same DB's
Application Type
Platform Version


I'm working on the Platform server upgrade from OS 10 to OS 11. 

I have a query while upgrading the Production environment that has 2 Servers (Farm mode - Primary and HA). Connected to MSSQL 2016 clustered instance.

We are planning to go by the Zero downtime approach where the Primary server will be disconnected from the load balancer and upgraded to OS 11 and testing the environment, followed by upgrading the HA server in a similar manner.

However, during the up-gradation process when the HA server is active and available for end-users, once we upgrade the Schema of the Database in the Configuration tool to OS 11, how will this impact the active HA server?

In summary, what will be the impact of running version 11 and 10 concurrently on the same database?

Please advise.

Thanks in Advance.


Purushothaman J

Rank: #71

Hello Purushothaman.

I've seen it done once.


The sequence is:

  1. Disabling the Front-end servers in Service Center.    
  2. Upgrade the platform in the controller node. 
  3. In the load balancer disconnect half of front-end servers in each zone.    
  4. Upgrade those servers and then enable them in Service Center    
  5. Switch the active Front-End servers in the Load Balancer to the upgraded ones    
  6. Upgrade the remaining Front-End servers.    
  7. Finally, reconnect all servers to the Load Balancer.

And don't forget Upgrade LifeTime.

Rank: #11363

Hello Nuno,

Thanks for your reply.

But my concern is, between steps 3 and 4. Which has one more step - Testing applications on the updated front-ends. The testing will take a day, during this time the Loaded Front End with OS 10 which is receiving traffic will throw any error or have any impact due to schema version mismatch in the Database?

Because we cannot afford any downtime.

Hope it's clear.

Purushothaman J

Rank: #71

Most of testing is done in non-production environment and you can take weeks if you want.

When doing it in production, the tests are basically on connections, the apps are good to go.