public class CqlOutputFormat extends AbstractColumnFamilyOutputFormat<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.List<java.nio.ByteBuffer>>
ColumnFamilyOutputFormat 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
ColumnFamily.
As is the case with the ColumnFamilyInputFormat,
you need to set the prepared statement in your
Hadoop job Configuration. The CqlConfigHelper class, through its
ConfigHelper#setOutputPreparedStatement 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.
BATCH_THRESHOLD, QUEUE_SIZE| Constructor and Description |
|---|
CqlOutputFormat() |
| Modifier and Type | Method and Description |
|---|---|
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
RecordWriter for the given task. |
checkOutputSpecs, checkOutputSpecs, checkOutputSpecs, createAuthenticatedClient, getOutputCommitter, login@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
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 © 2015 The Apache Software Foundation