In the Kettle Configuration file

To change the Jetty server parameters in the kettle.properties file, configure the following parameters to the numeric value you want. See Set Kettle Variables if you need more information on how to do this.

Kettle Variable in kettle.properties	Jetty Server Parameter
KETTLE_CARTE_JETTY_ACCEPTORS	acceptors
KETTLE_CARTE_JETTY_ACCEPT_QUEUE_SIZE	acceptQueueSize
KETTLE_CARTE_JETTY_RES_MAX_IDLE_TIME	lowResourcesMaxIdleTime