即使达到超时限制，Zookeeper 也不会使会话过期

Question

我在我的程序中观察到一个奇怪的问题，我正在使用一个独立的 zookeeper 并尝试为客户端模拟一个会话过期事件。现在，就我阅读文档和搜索互联网而言，我相信事件链如下进行。客户端连接到服务器并收到协商的超时，如果在超时期间没有从客户端收到心跳，服务器会使会话过期，即使客户端重新连接，它也会抛出一个会话过期 exception.Now 来模拟这个我已经编写了以下一段代码，但不知何故它工作得很好并且没有抛出会话过期异常。

    String path = "/SessionId3";
            ZooKeeper zoo;
            final CountDownLatch connectedSignal = new CountDownLatch(1);
            zoo = new ZooKeeper("localhost:2182", 5000, new Watcher() {

                public void process(WatchedEvent we) {
                    if (we.getState() == KeeperState.SyncConnected) {
                        System.out.println("in connected state");
                        connectedSignal.countDown();
                    }
                    if (we.getState() == KeeperState.Disconnected) {
                        System.out.println("in disconnected state");
                        connectedSignal.countDown();
                    }
                    if (we.getState() == KeeperState.Expired) {
                        System.out.println("in expired state");
                        connectedSignal.countDown();
                    }
                    if (we.getType() == Event.EventType.None) {
                        connectedSignal.countDown();
                    }
                }
            });

            System.out.println("in watcher");
            connectedSignal.await();
            long sId = zoo.getSessionId();
            System.out.println("sessionId=" + sId);
            byte[] sPwd = zoo.getSessionPasswd();
            System.out.println("session password=" + Arrays.toString(sPwd));
            long sTimeout=zoo.getSessionTimeout();
            System.out.println("agreed upon session timeout=" +sTimeout);   
            zoo.create(path,null,ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL);
            byte[] data=zoo.getData(path, new Watcher()
                    {
                public void process(WatchedEvent we)
                {
                    if(we.getType()==Event.EventType.NodeDeleted)
                    {
                        System.out.println("node deleted");
                    }
                }
                    }, null);
            System.out.println("disconnect from zookeeper servers.");
//here i kill my zookeeper server to make client disconnect
            Thread.sleep(30000);
            System.out.println("session must have expired...");
            Thread.sleep(10000);
            System.out.println("after sleep awakening");
//starting zookeeper server again to emulate reconnect
            Thread.sleep(10000);

            Stat stat = zoo.exists(path, false); //expected to get session expired exception but works fine?
    if (stat != null) 
            {System.out.println("fetching children");
                List<String> children=zoo.getChildren(path, false);
                for(String child:children)
                {
                    System.out.println(child);
                    byte[] b = zoo.getData(path+"/"+child, false, null);
                    String dataInString = new String(b, "UTF-8");
                    System.out.println(dataInString);
                }

            } else 
            {
                System.out.println("Node does not exists");
            }   
            zoo.close();//triggers the watch set on ephemeral node 

        }

我还有一个标准的 zoo.cfg 文件，它随 Zookeeper 一起提供。我做错了什么以及为什么我的会话永不过期？

Answer 1

好吧，我发现了问题（我猜）。问题似乎是当我依次关闭 zookeeper 服务器以模拟会话过期并且客户端继续重新连接但我错过的一点是 zookeeper 服务器管理会话过期以及当我关闭它并再次打开它时一段时间后，它会恢复从关闭时开始尝试连接的客户端的会话时间，这就是会话似乎永远不会过期的原因。为了证明我从另一台机器上尝试了客户端代码，然后关闭了它的连接，同时保持 zookeeper 服务器一直运行，一段时间后再次重新连接客户端并且 boom 在默认观察器中收到会话过期通知并得到 sessionexpired 异常。 .

即使达到超时限制，Zookeeper 也不会使会话过期

Zookeeper not expiring sessions even after timeout limit is reached

java

apache-zookeeper