I followed my normal procedure in updating our Jenkins builder:
- Update all Jenkins plugins first.
- Update jenkins core (using .war file)
I got the error message about JEP-200 and XStream, so I browsed to the wiki page. It had a note in there about -Dhudson.remoting.ClassFilter=, with a comma-separated list of class names from the log file. I got the list of classes:
So, I added those as a comma-separated list to -Dhudson.remoting.ClassFilter= and restarted Tomcat. Jenkins came back (authentication worked, but no build information is available, and slaves cannot connect), but I am now seeing a message about "You have data stored in an older format and/or unreadable data.". I am a bit afraid I will lose my build history and other metadata if I click on "Discard Unreadable Data". Is that a "safe" operation for my builds metadata?
Also, why do I need to add so many exclusions to the hudson.remoting.ClassFilter, some of which seem to be internal to jenkins/hudson? Shouldn't that "just work"? Did I do something wrong in the upgrade?