Combining multiple versions in one cluster

Couchbase Server
1

Hello all,

I’m new to the forums but I wanted to see if anyone could help me out. Right now I have a cluster 4 nodes running on version 3.0.1. We are in the process of trying to upgrade to 4.0.0 but we want to try it out on a single node first before making the transition to upgrading all 4.

I’ve tested this out locally where I was able to add a node that is running on 3.0.1 and one node is running on 4.0.0 in a cluster and all seems to be fine. My concern is that there are potentially some known issues or caveats to doing this approach that I don’t know about.

Has anyone else taken this approach to doing an upgrade before with these particular versions or could you think of any potential issues we may run into or things to look out for?

Thanks!

  • Michael F
2

Can you upgrade to 4.1 instead? The community edition will be available soon.

3

Does version 4.1 work better alongside 3.0.1? Right now We’re just trying to see if anyone has run into any issues having 2 different versions running together in one cluster. So essentially we would have 3 nodes on 3.0.1 and 1 node on 4.0.0 / 4.1 and we want to make sure there won’t be any issues with that.

4

Someone else will discuss the upgrade. I think a better option is to set up a second 4.x cluster and populate that using XDCR from the first cluster. My suggestion was that if you are upgrading, you should upgrade to 4.1 instead of 4.0.

5

We don’t recommend mixed clusters to run over long periods of time. If you are looking for a way to upgrade that allows you instant rollback, pls use XDCR. Set up a second cluster with the new version and set up bi directional replication between the old and new versions. Point your application to the new cluster to test in production and point back at the old version if you’d like to roll back. Obviously I highly recommend you rehearse this in a test env first.
thanks
-cihan

6

Awesome! Thanks all for the quick responses. I will recommend to the team that we do the seperate cluster with bi-directional replication method for now until the upgrade is ready.

Thanks again!

  • Michael F