Question

I try to write some data to hbase with a client program

HBase @ Hadoop runs in a preconfigured VM from Cloudera @ ubuntu.

The Client runs on the system hosting the VM and running the client directly in the VM works.

So now I want to use the client outside the vm to access the servers on the vm

I’m using NAT.
To be able to access the servers like HBase Master, HUE..running on the vm I configured port forwarding in virtual box:

Thus I can reach the overview sites of the HBase Master, HUE..

To run the client against the servers on the vm I created
hbase-site.xml with content:

<configuration>
    <property>
        <name>hbase.zookeeper.quorum</name>
        <value>localhost</value>
    </property>
    <property>
        <name>hbase.zookeeper.property.clientPort</name>
        <value>9997</value>
    </property>
    <property>
        <name>hbase.master</name>
        <value>localhost:9999</value>
    </property>
</configuration>

So I expected that forwarding works:

The error messages in the log when running the client looks like:

11/09/07 17:48:00 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
11/09/07 17:48:00 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/127.0.0.1:2181
11/09/07 17:48:01 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.ConnectException: Connection refused: no further information
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1119)
11/09/07 17:48:01 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/0:0:0:0:0:0:0:1:2181
11/09/07 17:48:01 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.SocketException: Address family not supported by protocol family: connect
    at sun.nio.ch.Net.connect(Native Method)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:500)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1050)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1077)
11/09/07 17:48:03 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/127.0.0.1:2181
11/09/07 17:48:04 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.ConnectException: Connection refused: no further information
    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1119)
11/09/07 17:48:04 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/0:0:0:0:0:0:0:1:2181
11/09/07 17:48:04 WARN zookeeper.ClientCnxn: Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect
java.net.SocketException: Address family not supported by protocol family: connect
    at sun.nio.ch.Net.connect(Native Method)
    at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:500)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1050)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1077)
11/09/07 17:48:05 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/127.0.0.1:2181

A correct connection log (when running the client directly on the vm) looks like:

11/09/07 09:05:29 INFO zookeeper.ZooKeeper: Initiating client connection, connectString=localhost:2181 sessionTimeout=180000 watcher=hconnection
11/09/07 09:05:29 INFO zookeeper.ClientCnxn: Opening socket connection to server localhost/0:0:0:0:0:0:0:1:2181
11/09/07 09:05:29 INFO zookeeper.ClientCnxn: Socket connection established to localhost/0:0:0:0:0:0:0:1:2181, initiating session
11/09/07 09:05:29 INFO zookeeper.ClientCnxn: Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x132449d36df0006, negotiated timeout = 40000

So I only see now in the log line before the first problem that connection url isn’t correct as the port is correctly forwarded but the IP is still localhost and not 10.0.2.15 as configured in the port forwarding settings:

Opening socket connection to server localhost/127.0.0.1:2181

Only hint I found is disabling IPV6 -> is disabled in host(win7) and vm(Ubuntu)
and checking the port -> they are correctly forwarded

Has anyone an idea?

Answer 1

Just to give an added value to users reading this, here is the solution:

Could not resolve the DNS name of cloudera-vm

To fix that I simply added to C:\Windows\System32\drivers\etc\hosts :

192.168.56.101  cloudera-vm

So whenever cloudera-vm is used it is resolved to the apropriate IP.
The VM is now running at Host-Only-Network Mode, and is assigned to 192.168.56.101 now.
So no port forwarding is necessary.

Just for comparison:

hbase-site.xml

<configuration>
  <property>
    <name>hbase.zookeeper.quorum</name>
    <value>cloudera-vm</value>
  </property>
</configuration>

persistence.xml

<persistence
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
    version="1.0">

    <persistence-unit name="hbase-addressbook"
        transaction-type="RESOURCE_LOCAL">

        <properties>
            <property name="datanucleus.ConnectionURL" value="hbase:cloudera-vm" />
            <property name="datanucleus.ConnectionUserName" value="" />
            <property name="datanucleus.ConnectionPassword" value="" />
            <property name="datanucleus.autoCreateSchema" value="true" />
            <property name="datanucleus.validateTables" value="false" />
            <property name="datanucleus.Optimistic" value="false" />
            <property name="datanucleus.validateConstraints" value="false" />
        </properties>
    </persistence-unit>
</persistence>

After that I got another error (connection refused although all connection strings were correct) thus I researched for days for the cause.

The solution was to disable IPV6 of Ubuntu running on the VM by appending the following to the file: /etc/sysctl.conf

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

After reboot everything connects and works correctly 🙂