When it starts a new job, Jenkins SGE Plugin tries to use an existing idle slave. If there are no idle slaves, a new slave is automatically provisioned.
When things are less busy, idle slaves are terminated after being idle for the Maximum idle time specified here.
Each project has a Workspace button that you can use to view the project workspace files in your web browser. This handy feature relies on the slave that executed the job. If the slave is gone, the workspace can no longer be viewed via the Jenkins web interface. If this happens often, consider increasing the Maximum idle time.
Note that the Maximum idle time applies only to newly provisioned slaves. Existing slaves retain the maximum idle time that was in effect when they were provisioned.
Handy conversions: