Package org.apache.cassandra.spark.bulkwriter

Class BroadcastableTokenPartitioner

java.lang.Object

org.apache.cassandra.spark.bulkwriter.BroadcastableTokenPartitioner

All Implemented Interfaces:

java.io.Serializable

public final class BroadcastableTokenPartitioner
extends java.lang.Object
implements java.io.Serializable

Broadcastable wrapper for TokenPartitioner with ZERO transient fields to optimize Spark broadcasting.

Only contains the partition mappings; executors will use this to reconstruct TokenPartitioner.

Why ZERO transient fields matters:
Spark's SizeEstimator uses reflection to estimate object sizes before broadcasting. Each transient field forces SizeEstimator to inspect the field's type hierarchy, which is expensive. Logger references are particularly costly due to their deep object graphs (appenders, layouts, contexts). By eliminating ALL transient fields and Logger references, we:

• Minimize SizeEstimator reflection overhead during broadcast preparation
• Reduce broadcast variable serialization size
• Avoid accidental serialization of non-serializable objects

See Also:

Serialized Form

Method Summary

Modifier and Type	Method	Description
static BroadcastableTokenPartitioner	from(TokenPartitioner source)	Creates a BroadcastableTokenPartitioner from a TokenPartitioner.
java.util.Map<com.google.common.collect.Range<java.math.BigInteger>,java.lang.Integer>	getPartitionEntries()
java.lang.Integer	numSplits()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

from

public static BroadcastableTokenPartitioner from(@NotNull
                                                 TokenPartitioner source)

Creates a BroadcastableTokenPartitioner from a TokenPartitioner. Extracts only the partition mappings, avoiding the Logger.

Parameters:

source - the source TokenPartitioner

getPartitionEntries

public java.util.Map<com.google.common.collect.Range<java.math.BigInteger>,java.lang.Integer> getPartitionEntries()

numSplits

public java.lang.Integer numSplits()