Monitor the waiting time for a network request to execute

[raskasa]

When troubleshooting a single network request it's worthwhile to see how much time passed between submitting the request and actual execution. This duration should preferably be close to 0 (when there was some idle thread in a pool), however it will grow when task has to be "queued". Moreover, if the pool doesn't have a fixed number of threads, running a new task might require spawning thread (also consuming short amount of time).

NOTE: Monitoring how long a task takes to execute is different from how long it took between when the task was submitted and when it was executed.

SEE: http://www.nurkiewicz.com/2014/11/executorservice-10-tips-and-tricks.html