TableMapReduceUtil (Apache HBase 1.1.7 API)

java.lang.Object
- org.apache.hadoop.hbase.mapred.TableMapReduceUtil

@InterfaceAudience.Public
@InterfaceStability.Stable
public class TableMapReduceUtil
extends Object

Utility for TableMap and TableReduce

Constructor Summary

Constructors
Constructor and Description

TableMapReduceUtil()

Constructors
Constructor and Description
`TableMapReduceUtil()`

Method Summary

Methods
Modifier and Type	Method and Description
`static void`	`addDependencyJars(org.apache.hadoop.mapred.JobConf job)`
`static void`	`initCredentials(org.apache.hadoop.mapred.JobConf job)`
`static void`	`initTableMapJob(String table, String columns, Class<? extends TableMap> mapper, Class<?> outputKeyClass, Class<?> outputValueClass, org.apache.hadoop.mapred.JobConf job)` Use this before submitting a TableMap job.
`static void`	`initTableMapJob(String table, String columns, Class<? extends TableMap> mapper, Class<?> outputKeyClass, Class<?> outputValueClass, org.apache.hadoop.mapred.JobConf job, boolean addDependencyJars)`
`static void`	`initTableMapJob(String table, String columns, Class<? extends TableMap> mapper, Class<?> outputKeyClass, Class<?> outputValueClass, org.apache.hadoop.mapred.JobConf job, boolean addDependencyJars, Class<? extends org.apache.hadoop.mapred.InputFormat> inputFormat)` Use this before submitting a TableMap job.
`static void`	`initTableReduceJob(String table, Class<? extends TableReduce> reducer, org.apache.hadoop.mapred.JobConf job)` Use this before submitting a TableReduce job.
`static void`	`initTableReduceJob(String table, Class<? extends TableReduce> reducer, org.apache.hadoop.mapred.JobConf job, Class partitioner)` Use this before submitting a TableReduce job.
`static void`	`initTableReduceJob(String table, Class<? extends TableReduce> reducer, org.apache.hadoop.mapred.JobConf job, Class partitioner, boolean addDependencyJars)` Use this before submitting a TableReduce job.
`static void`	`initTableSnapshotMapJob(String snapshotName, String columns, Class<? extends TableMap> mapper, Class<?> outputKeyClass, Class<?> outputValueClass, org.apache.hadoop.mapred.JobConf job, boolean addDependencyJars, org.apache.hadoop.fs.Path tmpRestoreDir)` Sets up the job for reading from a table snapshot.
`static void`	`limitNumMapTasks(String table, org.apache.hadoop.mapred.JobConf job)` Ensures that the given number of map tasks for the given job configuration does not exceed the number of regions for the given table.
`static void`	`limitNumReduceTasks(String table, org.apache.hadoop.mapred.JobConf job)` Ensures that the given number of reduce tasks for the given job configuration does not exceed the number of regions for the given table.
`static void`	`setNumMapTasks(String table, org.apache.hadoop.mapred.JobConf job)` Sets the number of map tasks for the given job configuration to the number of regions the given table has.
`static void`	`setNumReduceTasks(String table, org.apache.hadoop.mapred.JobConf job)` Sets the number of reduce tasks for the given job configuration to the number of regions the given table has.
`static void`	`setScannerCaching(org.apache.hadoop.mapred.JobConf job, int batchSize)` Sets the number of rows to return and cache with each scanner iteration.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TableMapReduceUtil
```
public TableMapReduceUtil()
```
- Method Detail
  - initTableMapJob
```
public static void initTableMapJob(String table,
                   String columns,
                   Class<? extends TableMap> mapper,
                   Class<?> outputKeyClass,
                   Class<?> outputValueClass,
                   org.apache.hadoop.mapred.JobConf job)
```
    Use this before submitting a TableMap job. It will appropriately set up the JobConf.
    
    Parameters:
    table - The table name to read from.
    columns - The columns to scan.
    mapper - The mapper class to use.
    outputKeyClass - The class of the output key.
    outputValueClass - The class of the output value.
    job - The current job configuration to adjust.
  - initTableMapJob
```
public static void initTableMapJob(String table,
                   String columns,
                   Class<? extends TableMap> mapper,
                   Class<?> outputKeyClass,
                   Class<?> outputValueClass,
                   org.apache.hadoop.mapred.JobConf job,
                   boolean addDependencyJars)
```
  - initTableMapJob
```
public static void initTableMapJob(String table,
                   String columns,
                   Class<? extends TableMap> mapper,
                   Class<?> outputKeyClass,
                   Class<?> outputValueClass,
                   org.apache.hadoop.mapred.JobConf job,
                   boolean addDependencyJars,
                   Class<? extends org.apache.hadoop.mapred.InputFormat> inputFormat)
```
    Use this before submitting a TableMap job. It will appropriately set up the JobConf.
    
    Parameters:
    table - The table name to read from.
    columns - The columns to scan.
    mapper - The mapper class to use.
    outputKeyClass - The class of the output key.
    outputValueClass - The class of the output value.
    job - The current job configuration to adjust.
    addDependencyJars - upload HBase jars and jars for any of the configured job classes via the distributed cache (tmpjars).
  - initTableSnapshotMapJob
```
public static void initTableSnapshotMapJob(String snapshotName,
                           String columns,
                           Class<? extends TableMap> mapper,
                           Class<?> outputKeyClass,
                           Class<?> outputValueClass,
                           org.apache.hadoop.mapred.JobConf job,
                           boolean addDependencyJars,
                           org.apache.hadoop.fs.Path tmpRestoreDir)
                                    throws IOException
```
    Sets up the job for reading from a table snapshot. It bypasses hbase servers and read directly from snapshot files.
    
    Parameters:
    snapshotName - The name of the snapshot (of a table) to read from.
    columns - The columns to scan.
    mapper - The mapper class to use.
    outputKeyClass - The class of the output key.
    outputValueClass - The class of the output value.
    job - The current job to adjust. Make sure the passed job is carrying all necessary HBase configuration.
    addDependencyJars - upload HBase jars and jars for any of the configured job classes via the distributed cache (tmpjars).
    tmpRestoreDir - a temporary directory to copy the snapshot files into. Current user should have write permissions to this directory, and this should not be a subdirectory of rootdir. After the job is finished, restore directory can be deleted.
    
    Throws:
    
    IOException - When setting up the details fails.
    See Also:
    TableSnapshotInputFormat
  - initTableReduceJob
```
public static void initTableReduceJob(String table,
                      Class<? extends TableReduce> reducer,
                      org.apache.hadoop.mapred.JobConf job)
                               throws IOException
```
    Use this before submitting a TableReduce job. It will appropriately set up the JobConf.
    
    Parameters:
    table - The output table.
    reducer - The reducer class to use.
    job - The current job configuration to adjust.
    
    Throws:
    
    IOException - When determining the region count fails.
  - initTableReduceJob
```
public static void initTableReduceJob(String table,
                      Class<? extends TableReduce> reducer,
                      org.apache.hadoop.mapred.JobConf job,
                      Class partitioner)
                               throws IOException
```
    Use this before submitting a TableReduce job. It will appropriately set up the JobConf.
    
    Parameters:
    table - The output table.
    reducer - The reducer class to use.
    job - The current job configuration to adjust.
    partitioner - Partitioner to use. Pass null to use default partitioner.
    
    Throws:
    
    IOException - When determining the region count fails.
  - initTableReduceJob
```
public static void initTableReduceJob(String table,
                      Class<? extends TableReduce> reducer,
                      org.apache.hadoop.mapred.JobConf job,
                      Class partitioner,
                      boolean addDependencyJars)
                               throws IOException
```
    Use this before submitting a TableReduce job. It will appropriately set up the JobConf.
    
    Parameters:
    table - The output table.
    reducer - The reducer class to use.
    job - The current job configuration to adjust.
    partitioner - Partitioner to use. Pass null to use default partitioner.
    addDependencyJars - upload HBase jars and jars for any of the configured job classes via the distributed cache (tmpjars).
    
    Throws:
    
    IOException - When determining the region count fails.
  - initCredentials
```
public static void initCredentials(org.apache.hadoop.mapred.JobConf job)
                            throws IOException
```
    Throws:
    
    IOException
  - limitNumReduceTasks
```
public static void limitNumReduceTasks(String table,
                       org.apache.hadoop.mapred.JobConf job)
                                throws IOException
```
    Ensures that the given number of reduce tasks for the given job configuration does not exceed the number of regions for the given table.
    
    Parameters:
    table - The table to get the region count for.
    job - The current job configuration to adjust.
    
    Throws:
    
    IOException - When retrieving the table details fails.
  - limitNumMapTasks
```
public static void limitNumMapTasks(String table,
                    org.apache.hadoop.mapred.JobConf job)
                             throws IOException
```
    Ensures that the given number of map tasks for the given job configuration does not exceed the number of regions for the given table.
    
    Parameters:
    table - The table to get the region count for.
    job - The current job configuration to adjust.
    
    Throws:
    
    IOException - When retrieving the table details fails.
  - setNumReduceTasks
```
public static void setNumReduceTasks(String table,
                     org.apache.hadoop.mapred.JobConf job)
                              throws IOException
```
    Sets the number of reduce tasks for the given job configuration to the number of regions the given table has.
    
    Parameters:
    table - The table to get the region count for.
    job - The current job configuration to adjust.
    
    Throws:
    
    IOException - When retrieving the table details fails.
  - setNumMapTasks
```
public static void setNumMapTasks(String table,
                  org.apache.hadoop.mapred.JobConf job)
                           throws IOException
```
    Sets the number of map tasks for the given job configuration to the number of regions the given table has.
    
    Parameters:
    table - The table to get the region count for.
    job - The current job configuration to adjust.
    
    Throws:
    
    IOException - When retrieving the table details fails.
  - setScannerCaching
```
public static void setScannerCaching(org.apache.hadoop.mapred.JobConf job,
                     int batchSize)
```
    Sets the number of rows to return and cache with each scanner iteration. Higher caching values will enable faster mapreduce jobs at the expense of requiring more heap to contain the cached rows.
    
    Parameters:
    job - The current job configuration to adjust.
    batchSize - The number of rows to return in batch with each scanner iteration.
  - addDependencyJars
```
public static void addDependencyJars(org.apache.hadoop.mapred.JobConf job)
                              throws IOException
```
    Throws:
    
    IOException
    See Also:
    TableMapReduceUtil.addDependencyJars(org.apache.hadoop.mapreduce.Job)

Class TableMapReduceUtil

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

TableMapReduceUtil

Method Detail

initTableMapJob

initTableMapJob

initTableMapJob

initTableSnapshotMapJob

initTableReduceJob

initTableReduceJob

initTableReduceJob

initCredentials

limitNumReduceTasks

limitNumMapTasks

setNumReduceTasks

setNumMapTasks

setScannerCaching

addDependencyJars