I have the following

OrderControl session bean which excepts an OrderModel javabean as a parameter,
this controls two entity beans Order and OrderLine - CMPs which maps to
respective tables. org.jboss.util.AutoNumberFactory is used to generate the
unique ids for both tables. org.jboss.ejb.plugins.TimedInstancePoolFeeder is
used in the OrderControl session bean configuration.

When I test this using JMeter with a test servlet that creates dummy orders
I get this... JMeter running only 5 threads, the system stops for 15 to 60 seconds
after a number of hits, it runs quickly and smoothly in between each.

eg
after 7 orders it stops for 17secs
after another 38 orders it stops for 17secs
after another 20 orders it stops for 51secs
after another 81 orders it stops for 17secs
after another 1 order it stops for 68secs

Is there any reason for this? Have I got my configurations wrong?