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org.apache.spark.streaming.dstream

MapWithStateDStream

sealed abstract class MapWithStateDStream[KeyType, ValueType, StateType, MappedType] extends DStream[MappedType]

DStream representing the stream of data generated by mapWithState operation on a pair DStream. Additionally, it also gives access to the stream of state snapshots, that is, the state data of all keys after a batch has updated them.

KeyType

Class of the key

ValueType

Class of the value

StateType

Class of the state data

MappedType

Class of the mapped data

Source
MapWithStateDStream.scala
Linear Supertypes
DStream[MappedType], Logging, Serializable, Serializable, AnyRef, Any
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  1. MapWithStateDStream
  2. DStream
  3. Logging
  4. Serializable
  5. Serializable
  6. AnyRef
  7. Any
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Abstract Value Members

  1. abstract def compute(validTime: Time): Option[RDD[MappedType]]

    Method that generates an RDD for the given time

    Method that generates an RDD for the given time

    Definition Classes
    DStream
  2. abstract def dependencies: List[DStream[_]]

    List of parent DStreams on which this DStream depends on

    List of parent DStreams on which this DStream depends on

    Definition Classes
    DStream
  3. abstract def slideDuration: Duration

    Time interval after which the DStream generates an RDD

    Time interval after which the DStream generates an RDD

    Definition Classes
    DStream
  4. abstract def stateSnapshots(): DStream[(KeyType, StateType)]

    Return a pair DStream where each RDD is the snapshot of the state of all the keys.

Concrete Value Members

  1. def cache(): DStream[MappedType]

    Persist RDDs of this DStream with the default storage level (MEMORY_ONLY_SER)

    Persist RDDs of this DStream with the default storage level (MEMORY_ONLY_SER)

    Definition Classes
    DStream
  2. def checkpoint(interval: Duration): DStream[MappedType]

    Enable periodic checkpointing of RDDs of this DStream

    Enable periodic checkpointing of RDDs of this DStream

    interval

    Time interval after which generated RDD will be checkpointed

    Definition Classes
    DStream
  3. def context: StreamingContext

    Return the StreamingContext associated with this DStream

    Return the StreamingContext associated with this DStream

    Definition Classes
    DStream
  4. def count(): DStream[Long]

    Return a new DStream in which each RDD has a single element generated by counting each RDD of this DStream.

    Return a new DStream in which each RDD has a single element generated by counting each RDD of this DStream.

    Definition Classes
    DStream
  5. def countByValue(numPartitions: Int = ssc.sc.defaultParallelism)(implicit ord: Ordering[MappedType] = null): DStream[(MappedType, Long)]

    Return a new DStream in which each RDD contains the counts of each distinct value in each RDD of this DStream.

    Return a new DStream in which each RDD contains the counts of each distinct value in each RDD of this DStream. Hash partitioning is used to generate the RDDs with numPartitions partitions (Spark's default number of partitions if numPartitions not specified).

    Definition Classes
    DStream
  6. def countByValueAndWindow(windowDuration: Duration, slideDuration: Duration, numPartitions: Int = ssc.sc.defaultParallelism)(implicit ord: Ordering[MappedType] = null): DStream[(MappedType, Long)]

    Return a new DStream in which each RDD contains the count of distinct elements in RDDs in a sliding window over this DStream.

    Return a new DStream in which each RDD contains the count of distinct elements in RDDs in a sliding window over this DStream. Hash partitioning is used to generate the RDDs with numPartitions partitions (Spark's default number of partitions if numPartitions not specified).

    windowDuration

    width of the window; must be a multiple of this DStream's batching interval

    slideDuration

    sliding interval of the window (i.e., the interval after which the new DStream will generate RDDs); must be a multiple of this DStream's batching interval

    numPartitions

    number of partitions of each RDD in the new DStream.

    Definition Classes
    DStream
  7. def countByWindow(windowDuration: Duration, slideDuration: Duration): DStream[Long]

    Return a new DStream in which each RDD has a single element generated by counting the number of elements in a sliding window over this DStream.

    Return a new DStream in which each RDD has a single element generated by counting the number of elements in a sliding window over this DStream. Hash partitioning is used to generate the RDDs with Spark's default number of partitions.

    windowDuration

    width of the window; must be a multiple of this DStream's batching interval

    slideDuration

    sliding interval of the window (i.e., the interval after which the new DStream will generate RDDs); must be a multiple of this DStream's batching interval

    Definition Classes
    DStream
  8. def filter(filterFunc: (MappedType) ⇒ Boolean): DStream[MappedType]

    Return a new DStream containing only the elements that satisfy a predicate.

    Return a new DStream containing only the elements that satisfy a predicate.

    Definition Classes
    DStream
  9. def flatMap[U](flatMapFunc: (MappedType) ⇒ TraversableOnce[U])(implicit arg0: ClassTag[U]): DStream[U]

    Return a new DStream by applying a function to all elements of this DStream, and then flattening the results

    Return a new DStream by applying a function to all elements of this DStream, and then flattening the results

    Definition Classes
    DStream
  10. def foreachRDD(foreachFunc: (RDD[MappedType], Time) ⇒ Unit): Unit

    Apply a function to each RDD in this DStream.

    Apply a function to each RDD in this DStream. This is an output operator, so 'this' DStream will be registered as an output stream and therefore materialized.

    Definition Classes
    DStream
  11. def foreachRDD(foreachFunc: (RDD[MappedType]) ⇒ Unit): Unit

    Apply a function to each RDD in this DStream.

    Apply a function to each RDD in this DStream. This is an output operator, so 'this' DStream will be registered as an output stream and therefore materialized.

    Definition Classes
    DStream
  12. def glom(): DStream[Array[MappedType]]

    Return a new DStream in which each RDD is generated by applying glom() to each RDD of this DStream.

    Return a new DStream in which each RDD is generated by applying glom() to each RDD of this DStream. Applying glom() to an RDD coalesces all elements within each partition into an array.

    Definition Classes
    DStream
  13. def map[U](mapFunc: (MappedType) ⇒ U)(implicit arg0: ClassTag[U]): DStream[U]

    Return a new DStream by applying a function to all elements of this DStream.

    Return a new DStream by applying a function to all elements of this DStream.

    Definition Classes
    DStream
  14. def mapPartitions[U](mapPartFunc: (Iterator[MappedType]) ⇒ Iterator[U], preservePartitioning: Boolean = false)(implicit arg0: ClassTag[U]): DStream[U]

    Return a new DStream in which each RDD is generated by applying mapPartitions() to each RDDs of this DStream.

    Return a new DStream in which each RDD is generated by applying mapPartitions() to each RDDs of this DStream. Applying mapPartitions() to an RDD applies a function to each partition of the RDD.

    Definition Classes
    DStream
  15. def persist(): DStream[MappedType]

    Persist RDDs of this DStream with the default storage level (MEMORY_ONLY_SER)

    Persist RDDs of this DStream with the default storage level (MEMORY_ONLY_SER)

    Definition Classes
    DStream
  16. def persist(level: StorageLevel): DStream[MappedType]

    Persist the RDDs of this DStream with the given storage level

    Persist the RDDs of this DStream with the given storage level

    Definition Classes
    DStream
  17. def print(num: Int): Unit

    Print the first num elements of each RDD generated in this DStream.

    Print the first num elements of each RDD generated in this DStream. This is an output operator, so this DStream will be registered as an output stream and there materialized.

    Definition Classes
    DStream
  18. def print(): Unit

    Print the first ten elements of each RDD generated in this DStream.

    Print the first ten elements of each RDD generated in this DStream. This is an output operator, so this DStream will be registered as an output stream and there materialized.

    Definition Classes
    DStream
  19. def reduce(reduceFunc: (MappedType, MappedType) ⇒ MappedType): DStream[MappedType]

    Return a new DStream in which each RDD has a single element generated by reducing each RDD of this DStream.

    Return a new DStream in which each RDD has a single element generated by reducing each RDD of this DStream.

    Definition Classes
    DStream
  20. def reduceByWindow(reduceFunc: (MappedType, MappedType) ⇒ MappedType, invReduceFunc: (MappedType, MappedType) ⇒ MappedType, windowDuration: Duration, slideDuration: Duration): DStream[MappedType]

    Return a new DStream in which each RDD has a single element generated by reducing all elements in a sliding window over this DStream.

    Return a new DStream in which each RDD has a single element generated by reducing all elements in a sliding window over this DStream. However, the reduction is done incrementally using the old window's reduced value :

    1. reduce the new values that entered the window (e.g., adding new counts) 2. "inverse reduce" the old values that left the window (e.g., subtracting old counts) This is more efficient than reduceByWindow without "inverse reduce" function. However, it is applicable to only "invertible reduce functions".
    reduceFunc

    associative and commutative reduce function

    invReduceFunc

    inverse reduce function; such that for all y, invertible x: invReduceFunc(reduceFunc(x, y), x) = y

    windowDuration

    width of the window; must be a multiple of this DStream's batching interval

    slideDuration

    sliding interval of the window (i.e., the interval after which the new DStream will generate RDDs); must be a multiple of this DStream's batching interval

    Definition Classes
    DStream
  21. def reduceByWindow(reduceFunc: (MappedType, MappedType) ⇒ MappedType, windowDuration: Duration, slideDuration: Duration): DStream[MappedType]

    Return a new DStream in which each RDD has a single element generated by reducing all elements in a sliding window over this DStream.

    Return a new DStream in which each RDD has a single element generated by reducing all elements in a sliding window over this DStream.

    reduceFunc

    associative and commutative reduce function

    windowDuration

    width of the window; must be a multiple of this DStream's batching interval

    slideDuration

    sliding interval of the window (i.e., the interval after which the new DStream will generate RDDs); must be a multiple of this DStream's batching interval

    Definition Classes
    DStream
  22. def repartition(numPartitions: Int): DStream[MappedType]

    Return a new DStream with an increased or decreased level of parallelism.

    Return a new DStream with an increased or decreased level of parallelism. Each RDD in the returned DStream has exactly numPartitions partitions.

    Definition Classes
    DStream
  23. def saveAsObjectFiles(prefix: String, suffix: String = ""): Unit

    Save each RDD in this DStream as a Sequence file of serialized objects.

    Save each RDD in this DStream as a Sequence file of serialized objects. The file name at each batch interval is generated based on prefix and suffix: "prefix-TIME_IN_MS.suffix".

    Definition Classes
    DStream
  24. def saveAsTextFiles(prefix: String, suffix: String = ""): Unit

    Save each RDD in this DStream as at text file, using string representation of elements.

    Save each RDD in this DStream as at text file, using string representation of elements. The file name at each batch interval is generated based on prefix and suffix: "prefix-TIME_IN_MS.suffix".

    Definition Classes
    DStream
  25. def slice(fromTime: Time, toTime: Time): Seq[RDD[MappedType]]

    Return all the RDDs between 'fromTime' to 'toTime' (both included)

    Return all the RDDs between 'fromTime' to 'toTime' (both included)

    Definition Classes
    DStream
  26. def slice(interval: Interval): Seq[RDD[MappedType]]

    Return all the RDDs defined by the Interval object (both end times included)

    Return all the RDDs defined by the Interval object (both end times included)

    Definition Classes
    DStream
  27. def transform[U](transformFunc: (RDD[MappedType], Time) ⇒ RDD[U])(implicit arg0: ClassTag[U]): DStream[U]

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream.

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream.

    Definition Classes
    DStream
  28. def transform[U](transformFunc: (RDD[MappedType]) ⇒ RDD[U])(implicit arg0: ClassTag[U]): DStream[U]

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream.

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream.

    Definition Classes
    DStream
  29. def transformWith[U, V](other: DStream[U], transformFunc: (RDD[MappedType], RDD[U], Time) ⇒ RDD[V])(implicit arg0: ClassTag[U], arg1: ClassTag[V]): DStream[V]

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream and 'other' DStream.

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream and 'other' DStream.

    Definition Classes
    DStream
  30. def transformWith[U, V](other: DStream[U], transformFunc: (RDD[MappedType], RDD[U]) ⇒ RDD[V])(implicit arg0: ClassTag[U], arg1: ClassTag[V]): DStream[V]

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream and 'other' DStream.

    Return a new DStream in which each RDD is generated by applying a function on each RDD of 'this' DStream and 'other' DStream.

    Definition Classes
    DStream
  31. def union(that: DStream[MappedType]): DStream[MappedType]

    Return a new DStream by unifying data of another DStream with this DStream.

    Return a new DStream by unifying data of another DStream with this DStream.

    that

    Another DStream having the same slideDuration as this DStream.

    Definition Classes
    DStream
  32. def window(windowDuration: Duration, slideDuration: Duration): DStream[MappedType]

    Return a new DStream in which each RDD contains all the elements in seen in a sliding window of time over this DStream.

    Return a new DStream in which each RDD contains all the elements in seen in a sliding window of time over this DStream.

    windowDuration

    width of the window; must be a multiple of this DStream's batching interval

    slideDuration

    sliding interval of the window (i.e., the interval after which the new DStream will generate RDDs); must be a multiple of this DStream's batching interval

    Definition Classes
    DStream
  33. def window(windowDuration: Duration): DStream[MappedType]

    Return a new DStream in which each RDD contains all the elements in seen in a sliding window of time over this DStream.

    Return a new DStream in which each RDD contains all the elements in seen in a sliding window of time over this DStream. The new DStream generates RDDs with the same interval as this DStream.

    windowDuration

    width of the window; must be a multiple of this DStream's interval.

    Definition Classes
    DStream