Hbase 2: Zookeeper ConnectionLossException: KeeperErrorCode = ConnectionLoss

[Martin Braun <ma...@zfabrik.de>]

Hi all,

I trying to import a backup of an hbase-1.0.6 export into a newly setup hbase-2.2.5 cluster.

When I run
 $NOSQL_HOME/hadoop-2.8.5/bin/yarn --config  $NOSQL_HOME/hadoop-2.8.5/etc/hadoop jar $HBASE_HOME/lib/hbase-mapreduce-2.2.5.jar import tt_items /TMPHDFS


The map reduce jobs starts on the nodes but after a while there are a dozen Exceptions:

Error: java.lang.RuntimeException: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase/hbaseid
        at org.apache.hadoop.hbase.mapreduce.Import$Importer.setup(Import.java:632)
        at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:143)
        at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
        at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:175)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1844)
        at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:169)
Caused by: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase/hbaseid
        at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
        at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
        at org.apache.zookeeper.ZooKeeper.exists(ZooKeeper.java:1045)
        at org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.exists(RecoverableZooKeeper.java:206)
        at org.apache.hadoop.hbase.zookeeper.ZKUtil.checkExists(ZKUtil.java:405)
        at org.apache.hadoop.hbase.zookeeper.ZKClusterId.readClusterIdZNode(ZKClusterId.java:65)
        at org.apache.hadoop.hbase.zookeeper.ZKClusterId.getUUIDForCluster(ZKClusterId.java:96)
        at org.apache.hadoop.hbase.mapreduce.Import$Importer.setup(Import.java:617)
        ... 8 more


In hadoop all-applications Website I than get the status FAILED.

I switched off firewalls, tested dns resolving, Configured Zookeeper Port 2181 is reachable from all nodes.

An   "echo mntr | nc Masternode 2181" shows a correct reply with date from zookeeper service. 

I also augmented the maxclientconnections of zookeeper in hnase-site.xml to 3000. It seems also that ther was data imported - but I am not sure if these errors are concerning?

But with no success.

Any ideas how to debug this?

Thanks in advance,
Martin