Best practices for upgrading Sitecore + coveo.
We have an older installation of Sitecore (7.0x) in our organization and are looking to integrate Coveo with Sitecore in the very near future. Muddying the waters is our plan to upgrade Sitecore from 7.0x to 7.5x in the next few months. As we understand it, Sitecore upgrades must be done at 0.1x intervals so, from 7.0x to 7.1x and so on.
I realize that we'll have to reinstall Coveo (version specific) once the Sitecore upgrade is complete. But are there any best practices we should keep in mind while doing this? Any major incompatibilities that we should be aware of, or is it recommended to finish upgrading Sitecore before installing Coveo for Sitecore?
I would say the best practice would be to wait until the you are at the latest version of Sitecore. If for any reasons, you which to have Coveo up and running on every versions, here is what I would do.
When installing on Sitecore 7.0, 7.1
Disable all lucene configuration files after installing Coveo, as Sitecore only support one index on these versions. Then when upgrading. Disable all Coveo configuration files and re-enable lucene. Then upload the new package, which will overwrite dlls, items and will generate new config files.
When installing on Sitecore 7.2+
You do not need to touch Lucene, simply enable the Coveo config files after the installation, and disable them prior to the upgrade.
For further readings: https://developers.coveo.com/display/public/SC201507/Best+Practices+When+Upgrading+Coveo+for+Sitecore