Hey Ryan,
I just got uploaded the small sample data into the Hbase-0.89. I will post
the Map Reduce code after completing the test. I need to get rid of the
exception which I am facing now. When I run the Map Reduce program in my
machine I am getting the following error.
................
................
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:317)
at org.apache.hadoop.mapred.Child$4.run(Child.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1063)
at org.apache.hadoop.mapred.Child.main(Child.java:211)
*attempt_201102010535_0004_m_000000_0:
org.apache.hadoop.hbase.client.NoServerForRegionException: Timed out trying
to locate root region*
attempt_201102010535_0004_m_000000_0: at
org.apache.hadoop.hbase.client.HConnectionManager$TableServers.locateRootRegion(HConnectionManager.java:1089)
attempt_201102010535_0004_m_000000_0: at
org.apache.hadoop.hbase.client.HConnectionManager$TableServers.locateRegion(HConnectionManager.java:668)
.........
....
Guess I had missing some of configuration in hadoop. Please help to resolve
this one..
Regards
Prabakaran
On Wed, Feb 2, 2011 at 11:05 PM, Jean-Daniel Cryans <[email protected]>wrote:
> Basically, BatchUpdate becomes Put and RowResult becomes Result.
>
> J-D
>
> On Tue, Feb 1, 2011 at 6:36 PM, Mark Kerzner <[email protected]>
> wrote:
> > Hi,
> >
> > below is a textbook example of using HBase from a MapReduce job. I am
> trying
> > to rewrite it in the 0.89 API, and I have not succeeded yet. Can
> > anyone please give me some pointers?
> >
> > Thank you very much. Sincerely,
> > Mark
> >
> > import java.io.IOException;
> > import java.util.Iterator;
> > import java.util.Map;
> > import org.apache.hadoop.conf.Configured;
> > import org.apache.hadoop.fs.Path;
> > import org.apache.hadoop.hbase.HBaseConfiguration;
> > import org.apache.hadoop.hbase.io.BatchUpdate;
> > import org.apache.hadoop.hbase.io.Cell;
> > import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
> > import org.apache.hadoop.hbase.io.RowResult;
> > import org.apache.hadoop.hbase.mapred.TableMap;
> > import org.apache.hadoop.hbase.mapred.TableMapReduceUtil;
> > import org.apache.hadoop.hbase.mapred.TableReduce;
> > import org.apache.hadoop.io.IntWritable;
> > import org.apache.hadoop.io.Text;
> > import org.apache.hadoop.mapred.FileOutputFormat;
> > import org.apache.hadoop.mapred.JobClient;
> > import org.apache.hadoop.mapred.JobConf;
> > import org.apache.hadoop.mapred.OutputCollector;
> > import org.apache.hadoop.mapred.Reporter;
> > import org.apache.hadoop.util.Tool;
> > import org.apache.hadoop.util.ToolRunner;
> >
> > public class MailboxIdCount extends Configured implements Tool {
> > // Name of this 'program'
> >
> > static final String NAME = "mailboxid-counter";
> > private static IntWritable ONE = new IntWritable(1);
> >
> > static class RowCounterMapper
> > implements TableMap<Text, IntWritable> {
> >
> > private static enum Counters {
> >
> > ROWS
> > }
> >
> > @Override
> > public void map(ImmutableBytesWritable row, RowResult value,
> > OutputCollector<Text, IntWritable> output,
> > Reporter reporter)
> > throws IOException {
> > for (Map.Entry<byte[], Cell> e : value.entrySet()) {
> > Cell cell = e.getValue();
> > if (cell != null && cell.getValue().length > 0) {
> > Text text = new Text(cell.getValue());
> > output.collect(text, ONE);
> > }
> > }
> >
> > }
> >
> > @Override
> > public void configure(JobConf jc) {
> > // Nothing to do.
> > }
> >
> > @Override
> > public void close() throws IOException {
> > // Nothing to do.
> > }
> > }
> >
> > public static class RowCounterReducer
> > implements TableReduce<Text, IntWritable> {
> >
> > @Override
> > public void configure(JobConf jc) {
> > // do nothing
> > }
> >
> > @Override
> > public void close() throws IOException {
> > // do nothing
> > }
> >
> > @Override
> > public void reduce(Text k2, Iterator<IntWritable> itrtr,
> > OutputCollector<ImmutableBytesWritable, BatchUpdate> oc, Reporter rprtr)
> > throws IOException {
> > int sum = 0;
> > while (itrtr.hasNext()) {
> > IntWritable val = itrtr.next();
> > sum += val.get();
> > }
> > String family = "stats:";
> > String familyCell = family + k2.toString();
> > BatchUpdate update = new BatchUpdate(k2.toString());
> > update.put(familyCell, String.valueOf(sum).getBytes());
> > oc.collect(new ImmutableBytesWritable(familyCell.getBytes()),
> > update);
> > }
> > }
> >
> > public JobConf createSubmittableJob(String[] args) throws IOException
> {
> > JobConf c = new JobConf(getConf(), getClass());
> > c.setJobName(NAME);
> > // Columns are space delimited
> > StringBuilder sb = new StringBuilder();
> > final int columnoffset = 2;
> > for (int i = columnoffset; i < args.length; i++) {
> > if (i > columnoffset) {
> > sb.append(" ");
> > }
> > sb.append(args[i]);
> > }
> > // Second argument is the table name.
> > TableMapReduceUtil.initTableMapJob(args[1], sb.toString(),
> > RowCounterMapper.class, Text.class, IntWritable.class, c);
> > TableMapReduceUtil.initTableReduceJob("mailbox-status",
> > RowCounterReducer.class, c);
> > // First arg is the output directory.
> > FileOutputFormat.setOutputPath(c, new Path(args[0]));
> > return c;
> > }
> >
> > static int printUsage() {
> > System.out.println(NAME
> > + " <outputdir> <tablename> <column1> [<column2>...]");
> > return -1;
> > }
> >
> > @Override
> > public int run(final String[] args) throws Exception {
> > // Make sure there are at least 3 parameters
> > if (args.length < 3) {
> > System.err.println("ERROR: Wrong number of parameters: " +
> > args.length);
> > return printUsage();
> > }
> > JobClient.runJob(createSubmittableJob(args));
> > return 0;
> > }
> >
> > public static void main(String[] args) throws Exception {
> > HBaseConfiguration c = new HBaseConfiguration();
> > int errCode = ToolRunner.run(c, new MailboxIdCount(), args);
> > System.exit(errCode);
> > }
> > }
> >
>
