java - hbase启动缓慢--调用观察程序时出错java.lang.NullPointerException : ZK is null

Question

最近与本地 0.94 hbase 建立连接的速度非常慢。我收到以下错误。我认为当我将我的 Mac 升级到 Yosemite 时，这种情况就开始发生了。我已经尝试了所有简单的修复、重新启动、清除 data/zk 目录、重新安装 hbase 等，但似乎没有任何帮助。

我的配置非常简单，只需覆盖 hbase.rootdir、hbase.zookeeper.quorum 和 hbase.zookeeper.property.dataDir 。我也收到这样的消息:

 java[3323:30250] Unable to load realm info from SCDynamicStore

但这些之前发生过，没有异常堆栈/非常慢的连接。

ZK is null on connection event -- see stack trace for the stack trace when constructor was called on this zkw
java.lang.Exception: ZKW CONSTRUCTOR STACK TRACE FOR DEBUGGING
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:143)
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.<init>(ZooKeeperWatcher.java:127)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getZooKeeperWatcher(HConnectionManager.java:1506)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.ensureZookeeperTrackers(HConnectionManager.java:714)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getMaster(HConnectionManager.java:787)
    at org.apache.hadoop.hbase.client.HBaseAdmin.<init>(HBaseAdmin.java:175)
    at com.feedly.normandy.persistence.hbase.PersistenceManager.init(PersistenceManager.java:244)
    at com.feedly.normandy.HBaseUnitTest.createPersistenceManager(HBaseUnitTest.java:152)
    at com.feedly.normandy.HBaseUnitTest.beforeClass(HBaseUnitTest.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

SEVERE: Error while calling watcher 
java.lang.NullPointerException: ZK is null
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.connectionEvent(ZooKeeperWatcher.java:366)
    at org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.process(ZooKeeperWatcher.java:303)
    at org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:519)
    at org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:495)

Answer 1

GrepCode Link Here声称 ZooKeeperWatcher 会抛出 NullPointerException，因为底层的 ZooKeeper 句柄在连接相关事件期间变为 null。 我建议在 ZK 主机上执行 netstat 并查看它是否在某个时刻断开连接。如果您没有看到这种情况发生，请下载此类的源 jar 并进入 connectionEvent() 方法以准确查看对象何时变为 null，这可能会导致您找到根本原因。