We recently upgraded an old rails app from rails 3 to 4.2, along with many other gem updates. Now I can't get my rails app to load any pages. We were on JRuby 9.1.0.0 but upgraded to 9.1.8.0. However, I'm hitting the same problem on both versions.
Once we start tomcat with our latest .war, it runs all the way until I see the INFO: Server startup in 1234ms message. I've added some debug statements in my rails environment / initializers files to follow it through and it is hitting each of them. So once I see the startup message from tomcat, I figured it would be okay. However, it immediately spits out the following message quite a few times:
DEBUG: resetting rack response due exception
Every time I load a URL, it also shows that message in my logs.
I see that it's from this jruby-rack class but I have no idea how to debug or troubleshoot this further.
I assume that something in my configuration is causing a problem or that a class/module is somehow short-circuiting it but I'm not sure how to identify which one it is or isolate the issue.
Does anybody know of a way to get some more verbose logs or ways to figure out where the problem is happening?
Happy to post any config/gemfiles etc if it will help.
After receiving some great help from the #jruby IRC channel, they mentioned the error message was missing the specific exception message. I was using the latest version, v1.1.21 so I just made a hack-build that added some logging to identify my problem further. Turns out it was a runtime error because of some missing config.
I made an issue with jruby-rack and a PR which will hopefully make its way into the next release!