You have to monitor a series of probes and report the data to a plotter. Since this is hardware, you have to request the data to the probe by calling probes.requestMetricFromProbe(probeName);

After that, the probe driver calls you back the method MonitoringSystem.receive on another thread.

Once that is called you have to call again requestMetricFromProbe to request data from the probe.

• Step1: Warmup

  • You have 1 probe: make sure you receive data and request a new sample immediately
  • Send every sample immediately to plotter (as a size-one list), from the same thread where the request() method runs
  • Rule: Plotter should receive the samples in their chronological order

• Step2: You have to support 3 probes

  • Rule: Plotter should only be sent one request at a time each time with a one-element list
    • Task: violate this rule and observe the exception
    • [Pro]: study how the detection of this case is implemented

• Step3: Request as many samples possible from the probe, as fast as possible

  • That is: you are NOT allowed to block in the thread running the receive()
  • Hint: You'll need your own thread pool. What kind?
    • Executors.newCachedThreadPool() creating unbounded threads or
    • Executors.newFixedThreadPool(N) creating a fixed number of threads; but N=?

• Step4: For memory efficiency, you should not keep more than 40 samples in memory

  • If too many samples arrive, discard the oldest (make the test pass)

• Step5: For network efficiency, Plotter now only accepts pages of 5 samples at a time

  • Hint: how do you accumulate a full page between threads?
  • IMPORTANT: don't mind about the previous test

• [HARD] Make the test still pass -> manual backpressure implementation

  • Hint: a queue of pages is too coarse-grained