matthew-dailey

public JavaDStream<Long> createLongStream(JavaDStream<Object> inputDStream) {
    return inputDStream.map(new ThreadUnsafeMapper());
  }

  private static class ThreadUnsafeMapper implements Function<Object, Long> {
    private static final long serialVersionUID = 1L;
    private long count = 0;

    // definitely not a thread-safe function
    @Override

matthew-dailey

  @Test
  public void deletemetest() throws InterruptedException {
    final BlockingQueue<Object> queue = Queues.newLinkedBlockingQueue();
    queue.offer("hello");

    Queue<Object> drain = Queues.newArrayDeque();
    Assert.assertEquals(1, queue.size());
    Assert.assertEquals(0, drain.size());

matthew-dailey

Building on Fedora 21

These instructions are for building mr4c on Fedora 21, written on March 15, 2015.

Installing Java dependencies

• Java (1.8.0_31)
• Download the Oracle JDK 1.8 and install.
• Historically, the OpenJDK that comes with many Linux distros has not worked well with Hadoop.
• Make sure to set JAVA_HOME to where you installed this.