Wed 10 Jun 2009 13:43
How well do Java Virtual Machines Scale Up?
Java seems to be a popular
language for small to medium-sized applications and its use at that scale is
well understood. But what happens when you scale it up
to something quite large? It seems that very large Java
Virtual Machines (JVMs) are still rather rare. Blackboard is a Java-based learning
management system (LMS) now in use at the University of Toronto. The University is
rather large, with a great many courses and students, and its Blackboard
JVM is correspondingly huge. It turns out that an ordinary off-the-shelf
JVM suffered some unusual and unpleasant performance issues (mostly related
to garbage collection) when scaled this large. The university
and Sun Microsystems eventually
resolved the issues quite nicely (using the new and still somewhat
experimental Java
G1 garbage collector) but it was an eventful journey.
John
Calvin of the University has put together
a rather interesting talk about this, which will be given
at the university on June 23rd, and later this summer at BBWorld 2009.