java Apache Curator分布式锁

Question

我知道Apache Curator可以在zookeeper的基础上实现分布式锁功能。基于Apache策展人官方网站上发布的文档，它看起来非常易于使用。例如：

RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
CuratorFramework client = CuratorFrameworkFactory.newClient("host:ip",retryPolicy);
client.start();

InterProcessSemaphoreMutex lock = new InterProcessSemaphoreMutex(client, path);
if(lock.acquire(10, TimeUnit.SECONDS))
{
     try { /*do something*/ }
     finally { lock.release(); }
}

但“进程间信号量emutex”的第二个参数“path”是什么意思？它的意思是基于API的“锁的路径”，但它到底是什么？谁能给我举个例子吗

如果我有数百万个锁，我需要创建数百万个“通往锁的路径”吗？zookeeper集群的最大锁数（znode）有限制吗？或者我们可以在进程释放锁时移除它吗

Answer 1

关于收割者的一些例子

@Test
public void     testSomeNodes() throws Exception
{

  Timing                  timing = new Timing();
  ChildReaper             reaper = null;
  CuratorFramework        client = CuratorFrameworkFactory.newClient(server.getConnectString(), timing.session(), timing.connection(), new RetryOneTime(1));
  try
  {
    client.start();

    Random              r = new Random();
    int                 nonEmptyNodes = 0;
    for ( int i = 0; i < 10; ++i )
    {
      client.create().creatingParentsIfNeeded().forPath("/test/" + Integer.toString(i));
      if ( r.nextBoolean() )
      {
        client.create().forPath("/test/" + Integer.toString(i) + "/foo");
        ++nonEmptyNodes;
      }
    }

    reaper = new ChildReaper(client, "/test", Reaper.Mode.REAP_UNTIL_DELETE, 1);
    reaper.start();

    timing.forWaiting().sleepABit();

    Stat    stat = client.checkExists().forPath("/test");
    Assert.assertEquals(stat.getNumChildren(), nonEmptyNodes);
  }
  finally
  {
    CloseableUtils.closeQuietly(reaper);
    CloseableUtils.closeQuietly(client);
  }
}

Java Code Examples for org.apache.curator.framework.recipes.locks.Reaper