Emit batch queue events for stress testing.

Hello @x-ma, @dpup, 

Please review the following commits I made in branch 'nathan-JubileeTestCluster'.

3097f1ffa2a6423aa649db6ee24d57a7ba29271e (2014-11-03 14:08:35 -0800)
Emit batch queue events for stress testing.

R=@x-ma
R=@dpup