We have a very old installation of Openfire 3.5.2. Does anyone have a recommended path to upgrade to 3.10? I expect that we may need to leapfrog through a few versions to get where we need to be. Any insight is greatly appreciated. Thanks.
First, make a backup.
Then i would just try installing 3.10.2 on top and let the upgrade script try do its job (it should automatically run all sql upgrade scripts to upgrade your database to the current schema). Upgrade will happen when you first launch it.
If this is not working, then restore your backup and try doing it in small steps. Like at first installing 3.6.4, then say 3.7.0, then 3.8.2 and so on. You can see all the release versions in the changelog. You can download all the installers by substituting version numbers in the download link.