Hi,
Is it necessary that all RegionServers must also be part of the ZK
Quorum? I have a 4 node cluster, with node hadoop1 being master and hadoop2,
hadoop3 and ejabber being the slaves (Both in case of hadoop and for HBase).
When I keep only 3 nodes in the zookeeper.quorum property:
<name>hbase.zookeeper.quorum</name>
<value>hadoop1,hadoop2,hadoop3</value>
I get this exception for all tasks that run on ejabber(the 4th node):
2010-11-21 23:35:47,785 INFO org.apache.zookeeper.ClientCnxn: Attempting
connection to server localhost/127.0.0.1:2181
2010-11-21 23:35:47,790 WARN org.apache.zookeeper.ClientCnxn: Exception
closing session 0x0 to sun.nio.ch.selectionkeyi...@7c2e1f1f
java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at
sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:574)
at
org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:933)
2010-11-21 23:35:47,791 WARN org.apache.zookeeper.ClientCnxn: Ignoring
exception during shutdown input
java.nio.channels.ClosedChannelException
at
sun.nio.ch.SocketChannelImpl.shutdownInput(SocketChannelImpl.java:638)
at sun.nio.ch.SocketAdaptor.shutdownInput(SocketAdaptor.java:360)
at
org.apache.zookeeper.ClientCnxn$SendThread.cleanup(ClientCnxn.java:999)
at
org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:970)
2010-11-21 23:35:47,791 WARN org.apache.zookeeper.ClientCnxn: Ignoring
exception during shutdown output
java.nio.channels.ClosedChannelException
at
sun.nio.ch.SocketChannelImpl.shutdownOutput(SocketChannelImpl.java:649)
at sun.nio.ch.SocketAdaptor.shutdownOutput(SocketAdaptor.java:368)
at
org.apache.zookeeper.ClientCnxn$SendThread.cleanup(ClientCnxn.java:1004)
at
org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:970)
2010-11-21 23:35:47,925 WARN
org.apache.hadoop.hbase.zookeeper.ZooKeeperWrapper: Failed to create /hbase
-- check quorum servers, currently=localhost:2181
org.apache.zookeeper.KeeperException$ConnectionLossException:
KeeperErrorCode = ConnectionLoss for /hbase
at
org.apache.zookeeper.KeeperException.create(KeeperException.java:90)
at
org.apache.zookeeper.KeeperException.create(KeeperException.java:42)
at org.apache.zookeeper.ZooKeeper.exists(ZooKeeper.java:780)
at org.apache.zookeeper.ZooKeeper.exists(ZooKeeper.java:808)
at
org.apache.hadoop.hbase.zookeeper.ZooKeeperWrapper.ensureExists(ZooKeeperWrapper.java:405)
at
org.apache.hadoop.hbase.zookeeper.ZooKeeperWrapper.ensureParentExists(ZooKeeperWrapper.java:432)
at
org.apache.hadoop.hbase.zookeeper.ZooKeeperWrapper.checkOutOfSafeMode(ZooKeeperWrapper.java:545)
When I add ejabber also to the ZK quorum and restart HBase, I don't get this
exception. My understanding was that a small cluster like mine should only
need one ZK machine.
Thanks,
Hari
