public class CqlOutputFormat
extends org.apache.hadoop.mapreduce.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>
implements org.apache.hadoop.mapred.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>
CqlOutputFormat acts as a Hadoop-specific
 OutputFormat that allows reduce tasks to store keys (and corresponding
 bound variable values) as CQL rows (and respective columns) in a given
 table.
 
 As is the case with the org.apache.cassandra.hadoop.ColumnFamilyInputFormat, 
 you need to set the prepared statement in your
 Hadoop job Configuration. The CqlConfigHelper class, through its
 CqlConfigHelper.setOutputCql(org.apache.hadoop.conf.Configuration, java.lang.String) method, is provided to make this
 simple.
 you need to set the Keyspace. The ConfigHelper class, through its
 ConfigHelper.setOutputColumnFamily(org.apache.hadoop.conf.Configuration, java.lang.String) method, is provided to make this
 simple.
 
For the sake of performance, this class employs a lazy write-back caching mechanism, where its record writer prepared statement binded variable values created based on the reduce's inputs (in a task-specific map), and periodically makes the changes official by sending a execution of prepared statement request to Cassandra.
| Modifier and Type | Field and Description | 
|---|---|
| static java.lang.String | BATCH_THRESHOLD | 
| static java.lang.String | QUEUE_SIZE | 
| Constructor and Description | 
|---|
| CqlOutputFormat() | 
| Modifier and Type | Method and Description | 
|---|---|
| protected void | checkOutputSpecs(org.apache.hadoop.conf.Configuration conf) | 
| void | checkOutputSpecs(org.apache.hadoop.fs.FileSystem filesystem,
                org.apache.hadoop.mapred.JobConf job)Deprecated.  | 
| void | checkOutputSpecs(org.apache.hadoop.mapreduce.JobContext context)Check for validity of the output-specification for the job. | 
| org.apache.hadoop.mapreduce.OutputCommitter | getOutputCommitter(org.apache.hadoop.mapreduce.TaskAttemptContext context)The OutputCommitter for this format does not write any data to the DFS. | 
| org.apache.cassandra.hadoop.cql3.CqlRecordWriter | getRecordWriter(org.apache.hadoop.fs.FileSystem filesystem,
               org.apache.hadoop.mapred.JobConf job,
               java.lang.String name,
               org.apache.hadoop.util.Progressable progress)Deprecated.  | 
| org.apache.cassandra.hadoop.cql3.CqlRecordWriter | getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext context)Get the  RecordWriterfor the given task. | 
public static final java.lang.String BATCH_THRESHOLD
public static final java.lang.String QUEUE_SIZE
public void checkOutputSpecs(org.apache.hadoop.mapreduce.JobContext context)
checkOutputSpecs in class org.apache.hadoop.mapreduce.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>context - information about the jobprotected void checkOutputSpecs(org.apache.hadoop.conf.Configuration conf)
@Deprecated
public void checkOutputSpecs(org.apache.hadoop.fs.FileSystem filesystem,
                                         org.apache.hadoop.mapred.JobConf job)
                                  throws java.io.IOException
checkOutputSpecs in interface org.apache.hadoop.mapred.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>java.io.IOExceptionpublic org.apache.hadoop.mapreduce.OutputCommitter getOutputCommitter(org.apache.hadoop.mapreduce.TaskAttemptContext context)
                                                               throws java.io.IOException,
                                                                      java.lang.InterruptedException
getOutputCommitter in class org.apache.hadoop.mapreduce.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>context - the task contextjava.io.IOExceptionjava.lang.InterruptedException@Deprecated
public org.apache.cassandra.hadoop.cql3.CqlRecordWriter getRecordWriter(org.apache.hadoop.fs.FileSystem filesystem,
                                                                                    org.apache.hadoop.mapred.JobConf job,
                                                                                    java.lang.String name,
                                                                                    org.apache.hadoop.util.Progressable progress)
                                                                             throws java.io.IOException
getRecordWriter in interface org.apache.hadoop.mapred.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>java.io.IOExceptionpublic org.apache.cassandra.hadoop.cql3.CqlRecordWriter getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext context)
                                                                 throws java.io.IOException,
                                                                        java.lang.InterruptedException
RecordWriter for the given task.getRecordWriter in class org.apache.hadoop.mapreduce.OutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>context - the information about the current task.RecordWriter to write the output for the job.java.io.IOExceptionjava.lang.InterruptedExceptionCopyright © 2018 The Apache Software Foundation