Tuning Java Garbage Collection for Web Services

Since I've been declared the local Java Garbage collection guru[1], I've found myself answering the same kinds of questions over and over. "Why am I getting frequent GC pauses?", "How do I avoid long GC pauses?", "Concurrent mode failure - how bad is that?" In the spirit of teaching people to fish, I thought I'd get together a blog post on how you (yes, you!) can tune the garbage collector for som