Advance notice of an imminent Full GC

[Denis Baranov]

Hi!

I was told at the JavaOne booth that it may be possible to expose
HotSpot's inner workings to the degree that when HotSpot makes the
decision to collect or not, those values it bases its decision upon
can be exposed via JMX and some application may be notified when
certain threshold is crossed. I think this would be helpful (in
absence of RealTime JVM) to be able to notify load balancer in
load-balanced configuration to stop sending requests to this instance,
force GC or wait for it to occur naturally, and then notify load
balancer again that the instance is ready to process requests.
Otherwise we observe situation when requests pile up at the "gate" and
cause an abrupt spike in load after Full GC.

Thanks!