hadoop클러스터를 구성 하던 서버중 HA를 담당하는 서버의 hostname등이 변경되었을때는 "hadoop-daemon.sh start zkfc"를 수행할때

아래와 같은 오류가 발생할 수 있는데 zookeeper내의 /hadoop-ha/mycluster 노드에 있는 정보가 변경된 사항을 반영하지 못해서 문제가

발생한것이다.

이때는 "hdfs zkfc -formatZK"를 실행하여 ZKFC정보를 재생성해준다.

-----------------hdfs zkfc -formatZK실행 로그----------------

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:java.library.path=:/svc/apps/sda/bin/hadoop/hadoop/lib/native

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:java.io.tmpdir=/tmp

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:java.compiler=<NA>

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:os.name=Linux

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:os.arch=amd64

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:os.version=2.6.32-573.22.1.el6.x86_64

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:user.name=root

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:user.home=/root

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Client environment:user.dir=/home/gooper/svc/apps/sda/bin/hadoop/hadoop-2.7.2/bin

16/07/29 19:30:43 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=gsda1:2181,gsda2:2181,gsda3:2181 sessionTimeout=5000 watcher=org.apache.hadoop.ha.ActiveStandbyElector$WatcherWithClientRef@1e178745

16/07/29 19:30:43 INFO zookeeper.ClientCnxn: Opening socket connection to server sda2/XXX.XXX.XXX.44:2181. Will not attempt to authenticate using SASL (unknown error)

16/07/29 19:30:43 INFO zookeeper.ClientCnxn: Socket connection established to sda2/XXX.XXX.XXX.44:2181, initiating session

16/07/29 19:30:43 INFO zookeeper.ClientCnxn: Session establishment complete on server sda2/XXX.XXX.XXX.44:2181, sessionid = 0x25634f0fabb0300, negotiated timeout = 5000

16/07/29 19:30:43 INFO ha.ActiveStandbyElector: Session connected.

===============================================

The configured parent znode /hadoop-ha/mycluster already exists.

Are you sure you want to clear all failover information from

ZooKeeper?

WARNING: Before proceeding, ensure that all HDFS services and

failover controllers are stopped!

===============================================

Proceed formatting /hadoop-ha/mycluster? (Y or N) Y

16/07/29 19:36:25 INFO ha.ActiveStandbyElector: Recursively deleting /hadoop-ha/mycluster from ZK...

16/07/29 19:36:25 INFO ha.ActiveStandbyElector: Successfully deleted /hadoop-ha/mycluster from ZK.

16/07/29 19:36:26 INFO ha.ActiveStandbyElector: Successfully created /hadoop-ha/mycluster in ZK.

16/07/29 19:36:26 INFO zookeeper.ZooKeeper: Session: 0x25634f0fabb0300 closed

16/07/29 19:36:26 INFO zookeeper.ClientCnxn: EventThread shut down

------------------오류내용-------------

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.library.path=/home/gooper/svc/apps/sda/bin/hadoop/hadoop-2.7.2/lib

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.io.tmpdir=/tmp

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:java.compiler=<NA>

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.name=Linux

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.arch=amd64

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:os.version=2.6.32-573.12.1.el6.x86_64

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.name=root

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.home=/root

2016-07-29 18:33:32,857 INFO org.apache.zookeeper.ZooKeeper: Client environment:user.dir=/home/gooper/svc/apps/sda/bin/hadoop/hadoop-2.7.2

2016-07-29 18:33:32,858 INFO org.apache.zookeeper.ZooKeeper: Initiating client connection, connectString=gsda1:2181,gsda2:2181,gsda3:2181 sessionTimeout=5000 watcher=org.apache.hadoop.ha.Ac

tiveStandbyElector$WatcherWithClientRef@52bf72b5

2016-07-29 18:33:32,936 FATAL org.apache.hadoop.hdfs.tools.DFSZKFailoverController: Got a fatal error, exiting now

java.net.UnknownHostException: gsda3: unknown error

        at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)

        at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)

        at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)

        at java.net.InetAddress.getAllByName0(InetAddress.java:1276)

        at java.net.InetAddress.getAllByName(InetAddress.java:1192)

        at java.net.InetAddress.getAllByName(InetAddress.java:1126)

        at org.apache.zookeeper.client.StaticHostProvider.<init>(StaticHostProvider.java:61)

        at org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:445)

        at org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:380)

        at org.apache.hadoop.ha.ActiveStandbyElector.getNewZooKeeper(ActiveStandbyElector.java:631)

        at org.apache.hadoop.ha.ActiveStandbyElector.createConnection(ActiveStandbyElector.java:775)

        at org.apache.hadoop.ha.ActiveStandbyElector.<init>(ActiveStandbyElector.java:229)

        at org.apache.hadoop.ha.ZKFailoverController.initZK(ZKFailoverController.java:350)

        at org.apache.hadoop.ha.ZKFailoverController.doRun(ZKFailoverController.java:191)

        at org.apache.hadoop.ha.ZKFailoverController.access$000(ZKFailoverController.java:61)

        at org.apache.hadoop.ha.ZKFailoverController$1.run(ZKFailoverController.java:172)

        at org.apache.hadoop.ha.ZKFailoverController$1.run(ZKFailoverController.java:168)

        at org.apache.hadoop.security.SecurityUtil.doAsLoginUserOrFatal(SecurityUtil.java:415)

        at org.apache.hadoop.ha.ZKFailoverController.run(ZKFailoverController.java:168)

        at org.apache.hadoop.hdfs.tools.DFSZKFailoverController.main(DFSZKFailoverController.java:181)