Trying to Connect with Oracle Direct Connector for Hadoop Distributed File System (HDFS) and getting java.sql.SQLRecoverableException: IO Error: Unknown host specified (Doc ID 1477476.1)

Last updated on JANUARY 03, 2017

Applies to:

Oracle Loader for Hadoop - Version 1.1.0 to 1.1.0 [Release 1.0]
Linux x86-64
***Checked for relevance on 30-Jun-2015***

Symptoms

 Trying to connect with Oracle Direct Connector for Hadoop Distributed File System (HDFS) and getting the following error:

java.sql.SQLRecoverableException: IO Error: Unknown host specified
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:458)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:546)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:236)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:521)
        at oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSource.java:280)
        at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:207)
        at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:157)
        at oracle.hadoop.hdfs.exttab.ExternalTable.getConnection(ExternalTable.java:206)
        at oracle.hadoop.hdfs.exttab.ExternalTable.publish(ExternalTable.java:242)
        at oracle.hadoop.hdfs.exttab.ExternalTable.run(ExternalTable.java:316)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
        at oracle.hadoop.hdfs.exttab.ExternalTable.main(ExternalTable.java:390)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.apache.hadoop.util.RunJar.main(RunJar.java:197)
Caused by: oracle.net.ns.NetException: Unknown host specified
        at oracle.net.resolver.HostnameNamingAdapter.resolve(HostnameNamingAdapter.java:191)
        at oracle.net.resolver.NameResolver.resolveName(NameResolver.java:133)
        at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.java:416)
        at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:687)
        at oracle.net.ns.NSProtocol.connect(NSProtocol.java:247)
        at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1102)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:320)
        ... 17 more

 

Cause

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