I'm working with a client which has some pretty old versions of the wso2 products on their estate and we're looking at options with regards to upgrading the following components:
wso2-esb 4.8.1 (target would be 7.x) wso2-apim 1.7.0 (target would be 4.1)
As stated these include quite large upgrades and I can't see a natural upgrade path especially as there has been the move to ballerina in the later products.
Can anyone offer advice on how to address such a hop in versions?
Migrating WSO2 ESB from 4.8.1 to MI 7.x should be fairly straightforward unless you have complex customizations. Ballerina is a totally different story as there is no easy migration path, you will mostly have to rewrite the code.
For APIM, it will be complex if you want to migrate, application data and other metadata. Also, WSO2 migration artifacts are only shared with subscription users. Having said that, you need to come up with your own strategy based on what you need to migrate. For example, migrating APIs can be done by exporting the swagger and importing them to the latest version.