How can I connect Hbase using Java Library(org.apache.hadoop.hbase.client) from different network?

Question

I have a Hadoop Cluster using inner network(ip range is 192.168.0.0/24), and I want to connect hbase using java library(org.apache.hadoop.hbase.client) from development computer on the Windows 7 that use different network(ip is outter network 203.252.xx), But, I couldn't connect hbase.

I Have a question.

1. Is my code wrong??

2. Is it possible using Java Library (org.apache.hadoop.hbase.client), should i use thrift protocol? (I don't want to use Thrift)

Do you have any idea? or comment ?

Thank you

This is My Code for Connecting Hbase.

---

 public class TestBase {
     public static void main(String[] args) throws MasterNotRunningException, ZooKeeperConnectionException, ServiceException, IOException {

    Configuration configuration = HBaseConfiguration.create();

    configuration.set("hbase.master", "203.252.x.x"); // master info
    configuration.set("hbase.master.port", "6000");
    configuration.set("hbase.zookeeper.quorum", "203.252.x.x");
    configuration.set("hbase.zookeeper.property.clientPort", "2181");
    configuration.set("zookeeper.znode.parent", "/hbase-unsecure"); 

    HBaseAdmin.checkHBaseAvailable(configuration);

    HTable table = null;
    table = new HTable(configuration, "weatherData");

    Scan scan = new Scan();

    scan.setTimeRange(1L, 1435633313526L);
    ResultScanner scanner = null;
    scanner = table.getScanner(scan);

    for (Result rr = scanner.next(); rr != null; rr = scanner.next()) {
        System.out.println(Bytes.toString(rr.getRow())
                + " => "
                + Bytes.toString(rr.getValue(Bytes.toBytes("temp"),
                        Bytes.toBytes("max"))));
    }
       table.close();
       scanner.close();
    }
}

and That is Error Code in Eclipse

log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" org.apache.hadoop.hbase.MasterNotRunningException: com.google.protobuf.ServiceException: java.net.UnknownHostException: unknown host: datanode2
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$StubMaker.makeStub(ConnectionManager.java:1661)
at enter code hereorg.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$MasterServiceStubMaker.makeStub(ConnectionManager.java:1687)
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.getKeepAliveMasterService(ConnectionManager.java:1904)
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.isMasterRunning(ConnectionManager.java:932)
at enter code hereorg.apache.hadoop.hbase.client.HBaseAdmin.checkHBaseAvailable(HBaseAdmin.java:2409)
at TestBase.main(TestBase.java:28)
Caused by: com.google.protobuf.ServiceException: java.net.UnknownHostException: unknown host: datanode2
at org.apache.hadoop.hbase.ipc.RpcClient.callBlockingMethod(RpcClient.java:1739)
at org.apache.hadoop.hbase.ipc.RpcClient$BlockingRpcChannelImplementation.callBlockingMethod(RpcClient.java:1777)
at org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$BlockingStub.isMasterRunning(MasterProtos.java:42561)
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$MasterServiceStubMaker.isMasterRunning(ConnectionManager.java:1698)
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$StubMaker.makeStubNoRetries(ConnectionManager.java:1607)
at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation$StubMaker.makeStub(ConnectionManager.java:1633)
... 5 more
Caused by: java.net.UnknownHostException: unknown host: datanode2
at org.apache.hadoop.hbase.ipc.RpcClient$Connection.<init>(RpcClient.java:501)
at org.apache.hadoop.hbase.ipc.RpcClient.createConnection(RpcClient.java:325)
at org.apache.hadoop.hbase.ipc.RpcClient.getConnection(RpcClient.java:1614)
at org.apache.hadoop.hbase.ipc.RpcClient.call(RpcClient.java:1494)
at org.apache.hadoop.hbase.ipc.RpcClient.callBlockingMethod(RpcClient.java:1724)
... 10 more

Answer 1

You are unable to reach to nodes of cluster. Check the firewall and network settings. Make sure ports are also open to connect.

This is error in you stack trace:

Exception in thread "main" org.apache.hadoop.hbase.MasterNotRunningException: com.google.protobuf.ServiceException: java.net.UnknownHostException: unknown host: datanode2

Also, you dont need to specify HBase cluster properties in your code. Put hbase-site.xml in classpath of your java and just instantiate the connection.

Answer 2

There might be a problem of the HBase Master DNS name mapping to the ip address of hbase.master. Be sure that you have either a DNS server set up or else you can try to find something similar to this that worked on my GNU/Linux machine. Such as configuring "/etc/hostname" :set up the name of the HBase Master node) and "/etc/hosts" on the machine that tries to connect to the master node.

Hopefully you can set up this on your Windows machine somehow.

Here is a helpful link for the GNU/Linux way:

http://sujee.net/2012/03/08/getting-dns-right-for-hadoop-hbase-clusters/#.XULnEZNKhTZ