Jenkins upgrade advice

Hey guys, thanks for taking the time to read this.

I’m a graduate DevOps engineer at my organisation and I have been tasked with trying to automate a Jenkins upgrade for all our instances (RHEL 7 servers) across the estate. I have written a role in ansible which automates the update using .rpm files and have tested that the role does correctly update the application.

I otherwise have very little to no experience at all using Jenkins and don’t know a whole lot about the application itself.

In my research I have seen conflicting information about which is the best method to upgrade Jenkins, but an incremental upgrade path seems to be the best approach, or most widely advised. Some of the oldest instances of Jenkins on our estate are sitting at version 2.121.x so are quite out of date.

I have read the upgrade path guide and I’m considering upgrading to the first release of each major version of Jenkins but I really dont understand all the specific pieces of information given about the changes made to the Jenkins application and what things I should DEFINITELY be doing before installing the next major version. Should I also be updating the plugins manually from the GUI after every single upgrade step or should I update the plugins after updating to the latest version of Jenkins first?

Any advice on this is really appreciated as I really don’t know what I’m doing. Thanks a lot.