com.rpl.rama

Interface PState.Declaration

Enclosing interface:

PState

public static interface PState.Declaration

Builder-style interface for specifying options when declaring a PState in a module

Method Summary

Modifier and Type	Method and Description
PState.Declaration	global() Configures PState to have a single partition.
PState.Declaration	initialValue(java.lang.Object val) Specifies starting value for PState.
<T,F extends RamaFunction2<java.lang.Integer,T,java.lang.Integer>> PState.Declaration	keyPartitioner(java.lang.Class<F> partitionerClass) Changes the default key partitioner to a custom one.
PState.Declaration	makePrivate() Configures PState to only be readable within the declaring topology.

Method Detail

global

PState.Declaration global()

Configures PState to have a single partition. Partition will be assigned to task 0.

initialValue

PState.Declaration initialValue(java.lang.Object val)

Specifies starting value for PState. This should only be used when top-level schema is declared with a Class.

makePrivate

PState.Declaration makePrivate()

Configures PState to only be readable within the declaring topology. Clients will not be able to retrieve this PState.

keyPartitioner

<T,F extends RamaFunction2<java.lang.Integer,T,java.lang.Integer>> PState.Declaration keyPartitioner(java.lang.Class<F> partitionerClass)

Changes the default key partitioner to a custom one. A key partitioner determines to which task to send a query request. It is used when a client calls select or selectAsync. The variants which only take a Path as input extract the partitioning key from the Path. The key partitioner is also used when calling select in ETL code.

The default key partitioner does hash-based partitioning.

Parameters:

partitionerClass - Function implementation which takes as input the number of partitions in the PState and the partitioning key. Returns the partition number to send the query request.