org.apache.tez.runtime.library.api
Interface Partitioner
public interface Partitioner
Partitioner is used by the TEZ framework to partition output
key/value pairs.
Partitioner Initialization
The Partitioner class is picked up
using the TEZ_RUNTIME_PARTITIONER_CLASS attribute in TezJobConfig
TODO NEWTEZ Change construction to first check for a Constructor with a bytep[] payload
Partitioners need to provide a single argument (Configuration)
constructor or a 0 argument constructor. If both exist, preference is given
to the single argument constructor. This is primarily for MR support.
If using the configuration constructor, TEZ_RUNTIME_NUM_EXPECTED_PARTITIONS
will be set in the configuration, to indicate the max number of expected
partitions.
getPartition
int getPartition(Object key,
Object value,
int numPartitions)
- Get partition for given key/value.
- Parameters:
key - keyvalue - valuenumPartitions - number of partitions
- Returns:
- partition for the given key/value
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