Whats the meaning of "remainingSeconds":XXXX,"type":"ACTIVE" in druid's supervisor's status

When I click on status of any supervisor many times I see “remainingSeconds”: NNN,“type”:“ACTIVE” in the status. But I don’t understand whats the meaning of this type: active and reaming seconds, remaining seconds for what? And sometimes these two keys don’t even appear, so I get too much confused why do they appear sometimes and why don’t they appear other times?