On April 24, 2006, I discovered what I believe is a leak in James (2.2.0)' DNS entries (largely using dnsjava).  I used Yourkit to take snapshots of the JVM (JDK 1.5.0_06) on linux (old rh).  Here are some relevant html reports from this:

• Objects by retained size
• 44 MB object's path to gc root
• 3 MB object's path to gc root
• 1 MB object's path to gc root

From these reports, you can see that about 49MB of 52MB total heap space is used by these DNS cache entries.  If we could figure out how to move these to disk based caching, this could dramatically improve the memory footprint of James.

Serge Knystautas sergek@lokitech.com