Release It! Second Edition: Please elaborate on block threads could be jettisoned, instead of making the external Integra calls (page 27)

It didn’t understand this line on page 27
“the clients could have been written so that blocked threads could have been jettisoned, instead of having the request handling thread make the external integration call”

“Request handling thread make the external integration call” - is it referring to the EJB RMI call as external integration? And suggesting it should have been done in a separate thread than request handling thread?

What are the ways to jettison blocked threads? Is there any example code out there for referrence?