zookeeper启动错误 transaction type: 2 error: KeeperErrorCode = NoNode for /hbase

hbase伪分布式，与zookeeper同一台机器的时候，运行一段时间，启动zookeeper的时候，日志中有如下错误，导致无法启动zookeeper

java.io.IOException: Failed to process transaction type: 2 error: KeeperErrorCode = NoNode for /hbase/unassigned
    at org.apache.zookeeper.server.persistence.FileTxnSnapLog.restore(FileTxnSnapLog.java:152)
    at org.apache.zookeeper.server.ZKDatabase.loadDataBase(ZKDatabase.java:222)
    at org.apache.zookeeper.server.ZooKeeperServer.loadData(ZooKeeperServer.java:239)
    at org.apache.zookeeper.server.ZooKeeperServer.startdata(ZooKeeperServer.java:366)
    at org.apache.zookeeper.server.NIOServerCnxn$Factory.startup(NIOServerCnxn.java:160)
    at org.apache.zookeeper.server.ZooKeeperServerMain.runFromConfig(ZooKeeperServerMain.java:110)
    at org.apache.hadoop.hbase.zookeeper.HQuorumPeer.runZKServer(HQuorumPeer.java:79)
    at org.apache.hadoop.hbase.zookeeper.HQuorumPeer.main(HQuorumPeer.java:64)

由于是伪分布式，zookeeper集成在hbase的机器上，hbase的临时目录默认是放在/tmp的，而linux的/tmp目录是会被定期清理的(参考linux系统的tmpwatch)

所以解决办法是，修改hbase-site.xml，指定hbase.tmp.dir，这样hbase的tmp目录不会被定时清理，over~

<configuration>

....(省略)

<property>
        <name>hbase.tmp.dir</name>
        <value>/hbase/tmp</value>
        <description>Temporary directory on the local filesystem.</description>
</property>

</configuration>