public void jsonSerializationOfExecutorRegistration() throws IOException {

    ObjectMapper mapper = new ObjectMapper();

    AppExecId appId = new AppExecId("foo", "bar");

    String appIdJson = mapper.writeValueAsString(appId);

    AppExecId parsedAppId = mapper.readValue(appIdJson, AppExecId.class);

    assertEquals(parsedAppId, appId);



    ExecutorShuffleInfo shuffleInfo =

      new ExecutorShuffleInfo(new String[]{"/bippy", "/flippy"}, 7, "hash");

    String shuffleJson = mapper.writeValueAsString(shuffleInfo);

    ExecutorShuffleInfo parsedShuffleInfo =

      mapper.readValue(shuffleJson, ExecutorShuffleInfo.class);

    assertEquals(parsedShuffleInfo, shuffleInfo);



    String legacyAppIdJson = "{"appId":"foo", "execId":"bar"}";

    assertEquals(appId, mapper.readValue(legacyAppIdJson, AppExecId.class));

    String legacyShuffleJson = "{"localDirs": ["/bippy", "/flippy"], " +

      ""subDirsPerLocalDir": 7, "shuffleManager": "hash"}";

    assertEquals(shuffleInfo, mapper.readValue(legacyShuffleJson, ExecutorShuffleInfo.class));

  }

    public void hundredStreamsConcurrently() throws Exception {

        ExecutorService e = Executors.newFixedThreadPool(5);

        for (int i = 0; i < 10; i++) {

            e.execute(new Runnable() {

                public void run() {

                    for (int i = 0; i < 10; i++) {

                        try {

                            isJarInputStreamReadable();

                        }

                        catch (Exception e) {

                            m_failure = e;

                        }

                    }

                }

            });

        }

        e.shutdown();

        e.awaitTermination(10, TimeUnit.SECONDS);



        assert m_failure == null : "Test failed: " + m_failure.getLocalizedMessage();

    }