Redmine

We have used Redmine for several years now with great success.
Setting up a new server I installed Redmine on Tomcat. We are using the Apache WEB server as front-end with the jk Apache Tomcat Connector to simplify the configuration.
The problem we have encountered is that the Redmine performance deteriorate with time (just a few hours use) and accessing issues results randomly in Internal error 500.
There is no trace of the error in the Tomcat log files.

Is Redmine known to be running stable on jruby Tomcat?

Our installation:

OS      OpenSUSE 13.1 x86_64
Tomcat  7.0.50
Java    1.7.0_51-b13

RAILS_ENV=production script/about
.../redmine-2.5.0/lib/redmine.rb:71 warning: already initialized constant FCSV

Environment:
  Redmine version                2.5.0.stable
  Ruby version                   1.9.3-p392 (2014-01-09) [java]
  Rails version                  3.2.17
  Environment                    production
  Database adapter               MySQL
SCM:
  Subversion                     1.8.8
  Filesystem                     
Redmine plugins:
  no plugin installed

production:
  adapter: mysql2
  database: redmine
  host: localhost
  username: redmine
  password: "***" 
  encoding: utf8