Hbase client ConnectionLoss for /hbase error

Question

I'm going completely crazy:

Installed Hadoop/Hbase, all is running;

/opt/jdk1.6.0_24/bin/jps
23261 ThriftServer
22582 QuorumPeerMain
21969 NameNode
23500 Jps
23021 HRegionServer
22211 TaskTracker
22891 HMaster
22117 SecondaryNameNode
21779 DataNode
22370 Main
22704 JobTracker

Pseudo distributed environment.

hbase shell

is working and coming up with correct results running 'list' and;

hbase shell
HBase Shell; enter 'help<RETURN>' for list of supported commands.
Type "exit<RETURN>" to leave the HBase Shell
Version 0.90.1-cdh3u0, r, Fri Mar 25 16:10:51 PDT 2011

hbase(main):001:0> status
1 servers, 0 dead, 8.0000 average load

When connecting via ruby & thrift, everything is working fine; we are adding data, it's getting in the system, we can query/scan it. Everything seems fine.

However, when connecting with Java:

groovy> import org.apache.hadoop.hbase.HBaseConfiguration 
groovy> import org.apache.hadoop.hbase.client.HBaseAdmin 
groovy> conf = HBaseConfiguration.create() 
groovy> conf.set("hbase.master","127.0.0.1:60000"); 
groovy> hbase = new HBaseAdmin(conf); 

Exception thrown

org.apache.hadoop.hbase.ZooKeeperConnectionException: org.apache.hadoop.hbase.ZooKeeperConnectionException: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /hbase
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getZooKeeperWatcher(HConnectionManager.java:1000)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.setupZookeeperTrackers(HConnectionManager.java:303)
    at org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.<init>(HConnectionManager.java:294)
    at org.apache.hadoop.hbase.client.HConnectionManager.getConnection(HConnectionManager.java:156)
    at org.apache.hadoop.hbase.client.HBaseAdmin.<init>(HBaseAdmin.java:84)

I've been trying to find the cause, but I really have no clue at all. Everything seems to be correctly installed.

netstat -lnp|grep 60000
tcp6       0      0 :::60000                :::*                    LISTEN      22891/java  

Looks fine as well.

# telnet localhost 60000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Connects and dies if you type anything + enter (not sure if that's the idea, thrift on 9090 does the same).

Can anyone help me?

Answer 1

The problem was actually that (for some reason ... I don't really get it in detail) the firewall was blocking one of the ports required to talk to Zookeeper; from the command line it worked, from my app it didn't. However when I disabled the firewall all worked fine all of a sudden.

Thank you for your help!