Thanks Kevin
I couldnt get it work. Here's the error I get:
bin/hadoop jar ~/dbload.jar LoadTable1
09/02/03 19:21:17 INFO jvm.JvmMetrics: Initializing JVM Metrics with
processName=JobTracker, sessionId=
09/02/03 19:21:20 INFO mapred.JobClient: Running job: job_local_0001
09/02/03 19:21:21 INFO mapred.JobClient: map 0% reduce 0%
09/02/03 19:21:22 INFO mapred.MapTask: numReduceTasks: 0
09/02/03 19:21:24 WARN mapred.LocalJobRunner: job_local_0001
java.io.IOException: ORA-00933: SQL command not properly ended
at
org.apache.hadoop.mapred.lib.db.DBInputFormat.getRecordReader(DBInputFormat.java:289)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:321)
at
org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:138)
java.io.IOException: Job failed!
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1217)
at LoadTable1.run(LoadTable1.java:130)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at LoadTable1.main(LoadTable1.java:107)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.hadoop.util.RunJar.main(RunJar.java:165)
at org.apache.hadoop.mapred.JobShell.run(JobShell.java:54)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at org.apache.hadoop.mapred.JobShell.main(JobShell.java:68)
Exception closing file
/user/amkhuran/contract_table/_temporary/_attempt_local_0001_m_000000_0/part-00000
java.io.IOException: Filesystem closed
at org.apache.hadoop.hdfs.DFSClient.checkOpen(DFSClient.java:198)
at org.apache.hadoop.hdfs.DFSClient.access$600(DFSClient.java:65)
at
org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.closeInternal(DFSClient.java:3084)
at
org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.close(DFSClient.java:3053)
at
org.apache.hadoop.hdfs.DFSClient$LeaseChecker.close(DFSClient.java:942)
at org.apache.hadoop.hdfs.DFSClient.close(DFSClient.java:210)
at
org.apache.hadoop.hdfs.DistributedFileSystem.close(DistributedFileSystem.java:243)
at
org.apache.hadoop.fs.FileSystem$Cache.closeAll(FileSystem.java:1413)
at org.apache.hadoop.fs.FileSystem.closeAll(FileSystem.java:236)
at
org.apache.hadoop.fs.FileSystem$ClientFinalizer.run(FileSystem.java:221)
Here's my code:
public class LoadTable1 extends Configured implements Tool {
// data destination on hdfs
private static final String CONTRACT_OUTPUT_PATH = "contract_table";
// The JDBC connection URL and driver implementation class
private static final String CONNECT_URL = "jdbc:oracle:thin:@dbhost
:1521:PSEDEV";
private static final String DB_USER = "user";
private static final String DB_PWD = "pass";
private static final String DATABASE_DRIVER_CLASS =
"oracle.jdbc.driver.OracleDriver";
private static final String CONTRACT_INPUT_TABLE = "OSE_EPR_CONTRACT";
private static final String [] CONTRACT_INPUT_TABLE_FIELDS = {
"PORTFOLIO_NUMBER", "CONTRACT_NUMBER"};
private static final String ORDER_CONTRACT_BY_COL = "CONTRACT_NUMBER";
static class ose_epr_contract implements Writable, DBWritable {
String CONTRACT_NUMBER;
public void readFields(DataInput in) throws IOException {
this.CONTRACT_NUMBER = Text.readString(in);
}
public void write(DataOutput out) throws IOException {
Text.writeString(out, this.CONTRACT_NUMBER);
}
public void readFields(ResultSet in_set) throws SQLException {
this.CONTRACT_NUMBER = in_set.getString(1);
}
@Override
public void write(PreparedStatement prep_st) throws SQLException {
// TODO Auto-generated method stub
}
}
public static class LoadMapper extends MapReduceBase
implements Mapper<LongWritable,
ose_epr_contract, Text, NullWritable> {
private static final char FIELD_SEPARATOR = 1;
public void map(LongWritable arg0, ose_epr_contract arg1,
OutputCollector<Text, NullWritable> arg2, Reporter arg3)
throws IOException {
StringBuilder sb = new StringBuilder();
;
sb.append(arg1.CONTRACT_NUMBER);
arg2.collect(new Text (sb.toString()), NullWritable.get());
}
}
public static void main(String[] args) throws Exception {
Class.forName("oracle.jdbc.driver.OracleDriver");
int exit = ToolRunner.run(new LoadTable1(), args);
}
public int run(String[] arg0) throws Exception {
JobConf conf = new JobConf(getConf(), LoadTable1.class);
conf.setInputFormat(DBInputFormat.class);
DBConfiguration.configureDB(conf, DATABASE_DRIVER_CLASS,
CONNECT_URL, DB_USER, DB_PWD);
DBInputFormat.setInput(conf, ose_epr_contract.class,
"select CONTRACT_NUMBER from OSE_EPR_CONTRACT",
"select COUNT(CONTRACT_NUMBER) from OSE_EPR_CONTRACT");
FileOutputFormat.setOutputPath(conf, new
Path(CONTRACT_OUTPUT_PATH));
conf.setMapperClass(LoadMapper.class);
conf.setNumReduceTasks(0);
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(NullWritable.class);
JobClient.runJob(conf);
return 0;
}
}
-Amandeep
Amandeep Khurana
Computer Science Graduate Student
University of California, Santa Cruz
On Tue, Feb 3, 2009 at 6:51 PM, Kevin Peterson <[email protected]> wrote:
> On Tue, Feb 3, 2009 at 5:49 PM, Amandeep Khurana <[email protected]> wrote:
>
> > In the setInput(...) function in DBInputFormat, there are two sets of
> > arguments that one can use.
> >
> > 1. public static void *setInput*(JobConf
> >
> > a) In this, do we necessarily have to give all the fieldNames (which are
> > the
> > column names right?) that the table has, or do we need to specify only
> the
> > ones that we want to extract?
>
>
> You may specify only those columns that you are interested in.
>
> b) Do we have to have a orderBy or not necessarily? Does this relate to the
> > primary key in the table in any ways?
>
>
> Conditions and order by are not necessary.
>
> a) Is there any restriction on the kind of queries that this function
> > can take in the inputQuery string?
>
>
> I don't think so, but I don't use this method -- I just use the fieldNames
> and tableName method.
>
>
> > I am facing issues in getting this to work with an Oracle database and
> > have no idea of how to debug it (an email sent earlier).
> > Can anyone give me some inputs on this please?
>
>
> Create a new table that has one column, put about five entries into that
> table, then try to get a map job working that outputs the values to a text
> file. If that doesn't work, post your code and errors.
>
