org.hammerlab.magic.rdd

CachedCountRegistry

class CachedCountRegistry extends AnyRef

CachedCountRegistry adds a .size method to RDDs that mimicks RDD.count, but caches its result.

It also exposes .sizes and .total on Seq[RDD]s, which compute the constituent RDDs' sizes (per above) in one Spark job.

Additionally, both sets of APIs optimize computations on UnionRDDs by computing their component RDDs' sizes and caching those as well as the UnionRDD's total.

Cached size info is keyed by a SparkContext for robustness in apps that stop their SparkContext and then resume with a new one; this is especially useful for testing!

Usage:

\ * import org.hammerlab.magic.rdd.CachedCountRegistry._
val rdd1 = sc.parallelize(0 until 4)
val rdd2 = sc.parallelize("a" :: "b" :: Nil)
rdd1.size()
(rdd1 :: rdd2 :: Nil).sizes()
(rdd1 :: rdd2 :: Nil).total()
Linear Supertypes
AnyRef, Any
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. CachedCountRegistry
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any

  3. final def ##(): Int

    Definition Classes
    AnyRef → Any

  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any

  6. final def asInstanceOf[T0]: T0

    Definition Classes
    Any

  7. def cachedCount(rdd: RDD[_]): Long

    Count RDD and cache result for RDD id

  8. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  9. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  10. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any

  11. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )

  12. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any

  13. def hashCode(): Int

    Definition Classes
    AnyRef → Any

  14. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any

  15. def multiCachedCount(rdds: Seq[RDD[_]]): Seq[Long]

    Compute multiple RDDs' sizes with a single Spark job; cache and return these sizes separately.

    Compute multiple RDDs' sizes with a single Spark job; cache and return these sizes separately.

    Along the way, this method will construct a UnionRDD from all non-cached, non-Union RDDs.

  16. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef

  17. final def notify(): Unit

    Definition Classes
    AnyRef

  18. final def notifyAll(): Unit

    Definition Classes
    AnyRef

  19. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef

  20. def toString(): String

    Definition Classes
    AnyRef → Any

  21. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  22. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  23. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

Inherited from AnyRef

Inherited from Any

Ungrouped