NFD

Test case to reproduce:

BOOST_FIXTURE_TEST_CASE(Overhead, TwoLaptopsFixture)
{
  /*
   *             /------------------\                              /------------------\
   *             | intervalConsumer |                              | intervalConsumer |
   *             \------------------/              A               \------------------/
   *                      ^ v                      f                        ^ v
   *                      | v /laptops/M           t                        | v /laptops/M
   *                      |                        e                        |
   *                      v                        r                        v
   *      /laptops << +--------+ >> /laptops                /laptops << +--------+ >> /laptops
   *           +----->| router |<------+           1             +----->| router |<------+
   *           |      +--------+       |                         |      +--------+       |
   *      10ms |                       | 20ms  === s ==>    10ms |                       | 20ms
   *           v                       v           e             v                       v
   *      +---------+             +---------+      c        +---------+             +---------+
   *      | laptopA |             | laptopB |      o        | laptopA |             | laptopB |
   *      +---------+             +---------+      n        +---------+             +---------+
   *           ^  v                                d
   *           |  v /laptops/M
   *           v
   *    /--------------\
   *    | echoProducer |
   *    \--------------/
   */

  // laptopA has prefix in router FIB; laptopB is unused in this test case
  topo.registerPrefix(router, linkA->getFace(router), "ndn:/laptops");
  topo.registerPrefix(router, linkB->getFace(router), "ndn:/laptops");

  shared_ptr<TopologyAppLink> producerA = topo.addAppFace(laptopA, "ndn:/laptops/A");
  topo.addEchoProducer(*producerA->getClientFace());

  // to build up "correct" RTO value
  shared_ptr<TopologyAppLink> consumer = topo.addAppFace(router);
  topo.addIntervalConsumer(*consumer->getClientFace(), "ndn:/laptops/A",
                           time::milliseconds(10), 100);
  this->advanceClocks(time::milliseconds(1), time::seconds(1));

  auto me = topo.getForwarder(router).getMeasurements().findLongestPrefixMatch("ndn:/laptops/A");
  BOOST_REQUIRE(me != nullptr);

  auto mi = me->getStrategyInfo<fw::AccessStrategy::MtInfo>();
  BOOST_REQUIRE(mi != nullptr);

  auto rto = mi->rtt.computeRto();
  BOOST_CHECK(time::milliseconds(10) < rto && rto < time::milliseconds(30));

  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 100);
  BOOST_CHECK_EQUAL(linkA->getFace(laptopA)->m_sentDatas.size(), 100);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 3);

  linkA->getFace(router)->m_sentInterests.clear();
  linkA->getFace(laptopA)->m_sentDatas.clear();
  linkB->getFace(router)->m_sentInterests.clear();

  // actual test
  producerA->fail();

  topo.addIntervalConsumer(*consumer->getClientFace(), "ndn:/laptops/A",
                           time::milliseconds(31), 10);

  // unicast to laptopA
  this->advanceClocks(time::milliseconds(1), time::milliseconds(10));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 1);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 0);

  // multicast
  this->advanceClocks(time::milliseconds(1), time::milliseconds(20));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 1);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 1);

  // unicast to laptopA
  this->advanceClocks(time::milliseconds(1), time::milliseconds(10));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 2);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 1);

  // multicast
  this->advanceClocks(time::milliseconds(1), time::milliseconds(20));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 2);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 2);

  // unicast to laptopA
  this->advanceClocks(time::milliseconds(1), time::milliseconds(10));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 3);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 2);

  // multicast
  this->advanceClocks(time::milliseconds(1), time::milliseconds(20));
  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 3);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 3);

  this->advanceClocks(time::milliseconds(5), time::seconds(1));

  BOOST_CHECK_EQUAL(linkA->getFace(router)->m_sentInterests.size(), 10);
  BOOST_CHECK_EQUAL(linkB->getFace(router)->m_sentInterests.size(), 10);

  this->advanceClocks(time::milliseconds(5), time::seconds(5));

  // all consumers should be done more than 4 seconds ago
  me = topo.getForwarder(router).getMeasurements().findLongestPrefixMatch("ndn:/laptops/A");
  BOOST_CHECK(me == nullptr);
}

Actual: (as shown in test assertions) after producer failure, Interests are unicasted to where the producer was, and then multicasted after an RTO. This continues until MeasurementsEntry expires.

Expected: after producer failure, Interests are multicasted right away.