I hope everyone is doing well in these special times.
As you can see in the title, we are looking at upgrading all our SAP ASE and SRS from 15.7 to 16. In this particular case we want to upgrade the primary data server and a replicate data server.
We are running on RHEL 7
Our setup is an bi-directional MSA environment.
ASE1 < ---------- > SRS1 < -------- > SRS2 < -------- > ASE2
So ASE1 is the primary and ASE2 is the replicate.
The strategy here would be to upgrade the ASE2 to ASE16 first, while the primary ASE1 is active for the application. When the upgrade for ASE2 is completed and all is good, we flip our application to ASE2, which becomes primary, and do the upgrade on ASE1, so really minimal downtime required.
It looks simple in the first place, but still will be complex.
We are considering doing the upgrade in-place, with installing ASE16 to a new folder on the existing hosts and using the sqlupgrade utility.
My other concern was about the repservers and the effect of the upgrade for the replicated databases.
But basically, we would suspend the route from SRS1 to SRS2, make sure everything coming from SRS1 is replicated to ASE2 and that SRS2 is quiesced, and then proceed with the steps for the upgrade process.
There is a section in the Install document about upgrading ASE in a replicated environment, but it doesn't really talk about anything really related to our setup.
Of course everything will be tested first in development to identify the issues and hiccups that we may face.
Does this approach sounds realistic? Is there anything more to do at the repserver level? Because basically, since ASE1 will be live while we upgrade ASE2, all the transactions are going to get stuck on the stable device of SRS1.