Hi everyone. I'm developing a monitoring app and I want to use Flink to process the event stream. I need to start a timer when an event is received in Flink, send the timer value and stop the timer when another event is received. Let me explain better. An event consists of an event name, a source id and other fields. So I have something like this:

E1("A",1,...) -> E2("B",1,...) -> E3("C",1,...)

When I receive event "A" I want to start a timer (keyed by the source id) and update a sink with the timer value periodically. When I receive event "C" I want to stop the timer and update the sink with the final timer value. Is there a way to accomplish that in Apache Flink?