zookeeper unable to open socket to localhost/0:0:0:0:0:0:0:1:2181

Question

I am using zookeeper ensemble for hbase. Zookeeper is running on 3 machines. While HBase is also in fully distributed mode. I have Nutch 2.x version. When I start nutch to crawl some data, it gives following buggs in nutch log file.

ERROR zookeeper.ClientCnxnSocketNIO - Unable to open socket to localhost/0:0:0:0:0:0:0:1:2181
2015-01-23 16:34:21,956 WARN  zookeeper.ClientCnxn - Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.SocketException: Network is unreachable
        at sun.nio.ch.Net.connect0(Native Method)
        at sun.nio.ch.Net.connect(Net.java:457)
        at sun.nio.ch.Net.connect(Net.java:449)
        at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:647)
        at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:266)
        at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:276)
        at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:958)
        at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:993)
2015-01-23 16:34:22,063 WARN  zookeeper.RecoverableZooKeeper - Possibly transient ZooKeeper exception: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase/hbaseid

When I run a command on three zookeepers instances

echo ruok | nc 1.1.1.1 2181 it says imok

What is wrong with it? My hbase version is 0.94.14 and zookeeper version is 3.4.5 , solr version 4.10.3 ( for indexing )and Nutch version is 2.2.3

Answer 1

( CentOS ) Check your /etc/hosts file and if it conatins like

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

change it to

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         ip6-localhost ip6-localhost.localdomain localhost6 localhost6.localdomain6