com.nvidia.spark.rapids.AbstractGpuJoinIterator.scala Maven / Gradle / Ivy
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Creates the distribution package of the RAPIDS plugin for Apache Spark
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/*
* Copyright (c) 2021-2024, NVIDIA CORPORATION.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.nvidia.spark.rapids
import ai.rapids.cudf.{GatherMap, NvtxColor, OutOfBoundsPolicy}
import com.nvidia.spark.rapids.Arm.withResource
import com.nvidia.spark.rapids.RapidsPluginImplicits._
import com.nvidia.spark.rapids.RmmRapidsRetryIterator.{splitTargetSizeInHalfGpu, withRestoreOnRetry, withRetry}
import com.nvidia.spark.rapids.ScalableTaskCompletion.onTaskCompletion
import org.apache.spark.TaskContext
import org.apache.spark.internal.Logging
import org.apache.spark.sql.catalyst.expressions.Attribute
import org.apache.spark.sql.catalyst.plans.{InnerLike, JoinType, LeftOuter, RightOuter}
import org.apache.spark.sql.vectorized.ColumnarBatch
trait TaskAutoCloseableResource extends AutoCloseable {
protected var closed = false
// iteration-independent resources
private val resources = scala.collection.mutable.ArrayBuffer[AutoCloseable]()
def use[T <: AutoCloseable](ac: T): T = {
resources += ac
ac
}
override def close() = if (!closed) {
closed = true
resources.reverse.safeClose()
resources.clear()
}
// Don't install the callback if in a unit test
Option(TaskContext.get()).foreach { tc =>
onTaskCompletion(tc) {
close()
}
}
}
/**
* Base class for iterators producing the results of a join.
* @param gatherNvtxName name to use for the NVTX range when producing the join gather maps
* @param targetSize configured target batch size in bytes
* @param opTime metric to record op time in the iterator
* @param joinTime metric to record GPU time spent in join
*/
abstract class AbstractGpuJoinIterator(
gatherNvtxName: String,
targetSize: Long,
val opTime: GpuMetric,
joinTime: GpuMetric)
extends Iterator[ColumnarBatch] with TaskAutoCloseableResource {
private[this] var nextCb: Option[ColumnarBatch] = None
private[this] var gathererStore: Option[JoinGatherer] = None
/** Returns whether there are any more batches on the stream side of the join */
protected def hasNextStreamBatch: Boolean
/**
* Called to setup the next join gatherer instance when the previous instance is done or
* there is no previous instance. Because this is likely to call next or has next on the
* stream side all implementations must track their own opTime metrics.
* @return some gatherer to use next or None if there is no next gatherer or the loop should try
* to build the gatherer again (e.g.: to skip a degenerate join result batch)
*/
protected def setupNextGatherer(): Option[JoinGatherer]
/** Whether to automatically call close() on this iterator when it is exhausted. */
protected val shouldAutoCloseOnExhaust: Boolean = true
override def hasNext: Boolean = {
if (closed) {
return false
}
var mayContinue = true
while (nextCb.isEmpty && mayContinue) {
if (gathererStore.exists(!_.isDone)) {
opTime.ns {
nextCb = nextCbFromGatherer()
}
} else {
if (hasNextStreamBatch) {
// Need to refill the gatherer
opTime.ns {
gathererStore.foreach(_.close())
gathererStore = None
}
gathererStore = setupNextGatherer()
opTime.ns {
nextCb = nextCbFromGatherer()
}
} else {
mayContinue = false
}
}
}
if (nextCb.isEmpty && shouldAutoCloseOnExhaust) {
// Nothing is left to return so close ASAP.
opTime.ns(close())
}
nextCb.isDefined
}
override def next(): ColumnarBatch = {
if (!hasNext) {
throw new NoSuchElementException()
}
val ret = nextCb.get
nextCb = None
ret
}
override def close(): Unit = {
if (!closed) {
nextCb.foreach(_.close())
nextCb = None
gathererStore.foreach(_.close())
gathererStore = None
closed = true
}
}
private def nextCbFromGatherer(): Option[ColumnarBatch] = {
withResource(new NvtxWithMetrics(gatherNvtxName, NvtxColor.DARK_GREEN, joinTime)) { _ =>
val minTargetSize = Math.min(targetSize, 64L * 1024 * 1024)
val targetSizeWrapper = AutoCloseableTargetSize(targetSize, minTargetSize)
val ret = gathererStore.map { gather =>
// This withRetry block will always return an iterator with one ColumnarBatch.
// The gatherer tracks how many rows we have used already. The withRestoreOnRetry
// ensures that we restart at the same place in the gatherer. In the case of a
// GpuSplitAndRetryOOM, we retry with a smaller (halved) targetSize, so we are taking
// less from the gatherer, but because the gatherer tracks how much is used, the
// next call to this function will start in the right place.
gather.checkpoint()
withRetry(targetSizeWrapper, splitTargetSizeInHalfGpu) { attempt =>
withRestoreOnRetry(gather) {
val nextRows = JoinGatherer.getRowsInNextBatch(gather, attempt.targetSize)
gather.gatherNext(nextRows)
}
}.next()
}
if (gathererStore.exists(_.isDone)) {
gathererStore.foreach(_.close())
gathererStore = None
}
if (ret.isDefined) {
// We are about to return something. We got everything we need from it so now let it spill
// if there is more to be gathered later on.
gathererStore.foreach(_.allowSpilling())
}
ret
}
}
}
/**
* Base class for join iterators that split and spill batches to avoid GPU OOM errors.
* @param gatherNvtxName name to use for the NVTX range when producing the join gather maps
* @param stream iterator to produce the batches for the streaming side input of the join
* @param streamAttributes attributes corresponding to the streaming side input
* @param builtBatch batch for the built side input of the join
* @param targetSize configured target batch size in bytes
* @param opTime metric to record time spent for this operation
* @param joinTime metric to record GPU time spent in join
*/
abstract class SplittableJoinIterator(
gatherNvtxName: String,
stream: Iterator[LazySpillableColumnarBatch],
streamAttributes: Seq[Attribute],
builtBatch: LazySpillableColumnarBatch,
targetSize: Long,
opTime: GpuMetric,
joinTime: GpuMetric)
extends AbstractGpuJoinIterator(
gatherNvtxName,
targetSize,
opTime = opTime,
joinTime = joinTime) with Logging {
// For some join types even if there is no stream data we might output something
private var isInitialJoin = true
// If the join explodes this holds batches from the stream side split into smaller pieces.
private val pendingSplits = scala.collection.mutable.Queue[LazySpillableColumnarBatch]()
protected def computeNumJoinRows(cb: LazySpillableColumnarBatch): Long
/**
* Create a join gatherer.
* @param cb next column batch from the streaming side of the join
* @param numJoinRows if present, the number of join output rows computed for this batch
* @return some gatherer to use next or None if there is no next gatherer or the loop should try
* to build the gatherer again (e.g.: to skip a degenerate join result batch)
*/
protected def createGatherer(cb: LazySpillableColumnarBatch,
numJoinRows: Option[Long]): Option[JoinGatherer]
override def hasNextStreamBatch: Boolean = {
isInitialJoin || pendingSplits.nonEmpty || stream.hasNext
}
override def setupNextGatherer(): Option[JoinGatherer] = {
val wasInitialJoin = isInitialJoin
isInitialJoin = false
if (pendingSplits.nonEmpty || stream.hasNext) {
val scb = if (pendingSplits.nonEmpty) {
pendingSplits.dequeue()
} else {
stream.next()
}
opTime.ns {
withResource(scb) { scb =>
val numJoinRows = computeNumJoinRows(scb)
// We want the gather maps size to be around the target size. There are two gather maps
// that are made up of ints, so compute how many rows on the stream side will produce the
// desired gather maps size.
val maxJoinRows = Math.max(1, targetSize / (2 * Integer.BYTES))
if (numJoinRows > maxJoinRows && scb.numRows > 1) {
// Need to split the batch to reduce the gather maps size. This takes a simplistic
// approach of assuming the data is uniformly distributed in the stream table.
val numSplits = Math.min(scb.numRows,
Math.ceil(numJoinRows.toDouble / maxJoinRows).toInt)
splitAndSave(scb.getBatch, numSplits)
// Return no gatherer so the outer loop will try again
return None
}
createGatherer(scb, Some(numJoinRows))
}
}
} else {
opTime.ns {
assert(wasInitialJoin)
import scala.collection.JavaConverters._
withResource(GpuColumnVector.emptyBatch(streamAttributes.asJava)) { cb =>
withResource(LazySpillableColumnarBatch(cb, "empty_stream")) { scb =>
createGatherer(scb, None)
}
}
}
}
}
override def close(): Unit = {
if (!closed) {
super.close()
builtBatch.close()
pendingSplits.foreach(_.close())
pendingSplits.clear()
}
}
private def splitStreamBatch(
cb: ColumnarBatch,
numBatches: Int): Seq[LazySpillableColumnarBatch] = {
val batchSize = cb.numRows() / numBatches
val splits = withResource(GpuColumnVector.from(cb)) { tab =>
val splitIndexes = (1 until numBatches).map(num => num * batchSize)
tab.contiguousSplit(splitIndexes: _*)
}
withResource(splits) { splits =>
val schema = GpuColumnVector.extractTypes(cb)
withResource(splits.safeMap(_.getTable)) { tables =>
withResource(tables.safeMap(GpuColumnVector.from(_, schema))) { batches =>
batches.safeMap { splitBatch =>
val lazyCb = LazySpillableColumnarBatch(splitBatch, "stream_data")
lazyCb.allowSpilling()
lazyCb
}
}
}
}
}
/**
* Split a stream-side input batch, making all splits spillable, and replacing this batch with
* the splits in the stream-side input
* @param cb stream-side input batch to split
* @param numBatches number of splits to produce with approximately the same number of rows each
* @param oom a prior OOM exception that this will try to recover from by splitting
*/
protected def splitAndSave(
cb: ColumnarBatch,
numBatches: Int,
oom: Option[Throwable] = None): Unit = {
val batchSize = cb.numRows() / numBatches
if (oom.isDefined && batchSize < 100) {
// We just need some kind of cutoff to not get stuck in a loop if the batches get to be too
// small but we want to at least give it a chance to work (mostly for tests where the
// targetSize can be set really small)
throw oom.get
}
val msg = s"Split stream batch into $numBatches batches of about $batchSize rows"
if (oom.isDefined) {
logWarning(s"OOM Encountered: $msg")
} else {
logInfo(msg)
}
pendingSplits ++= splitStreamBatch(cb, numBatches)
}
/**
* Create a join gatherer from gather maps.
* @param maps gather maps produced from a cudf join
* @param leftData batch corresponding to the left table in the join
* @param rightData batch corresponding to the right table in the join
* @return some gatherer or None if the are no rows to gather in this join batch
*/
protected def makeGatherer(
maps: Array[GatherMap],
leftData: LazySpillableColumnarBatch,
rightData: LazySpillableColumnarBatch,
joinType: JoinType): Option[JoinGatherer] = {
assert(maps.length > 0 && maps.length <= 2)
try {
val leftGatherer = joinType match {
case LeftOuter if maps.length == 1 =>
// Distinct left outer joins only produce a single gather map since left table rows
// are not rearranged by the join.
new JoinGathererSameTable(leftData)
case _ =>
val lazyLeftMap = LazySpillableGatherMap(maps.head, "left_map")
// Inner joins -- manifest the intersection of both left and right sides. The gather maps
// contain the number of rows that must be manifested, and every index
// must be within bounds, so we can skip the bounds checking.
//
// Left outer -- Left outer manifests all rows for the left table. The left gather map
// must contain valid indices, so we skip the check for the left side.
val leftOutOfBoundsPolicy = joinType match {
case _: InnerLike | LeftOuter => OutOfBoundsPolicy.DONT_CHECK
case _ => OutOfBoundsPolicy.NULLIFY
}
JoinGatherer(lazyLeftMap, leftData, leftOutOfBoundsPolicy)
}
val rightMap = joinType match {
case _ if rightData.numCols == 0 => None
case LeftOuter if maps.length == 1 =>
// Distinct left outer joins only produce a single gather map since left table rows
// are not rearranged by the join.
Some(maps.head)
case _ if maps.length == 1 => None
case _ => Some(maps(1))
}
val gatherer = rightMap match {
case None if joinType == RightOuter && rightData.numCols > 0 =>
// Distinct right outer joins only produce a single gather map since right table rows
// are not rearranged by the join.
MultiJoinGather(leftGatherer, new JoinGathererSameTable(rightData))
case None =>
// When there isn't a `rightMap` we are in either LeftSemi or LeftAnti joins.
// In these cases, the map and the table are both the left side, and everything in the map
// is a match on the left table, so we don't want to check for bounds.
rightData.close()
leftGatherer
case Some(right) =>
// Inner joins -- manifest the intersection of both left and right sides. The gather maps
// contain the number of rows that must be manifested, and every index
// must be within bounds, so we can skip the bounds checking.
//
// Right outer -- Is the opposite from left outer (skip right bounds check, keep left)
val rightOutOfBoundsPolicy = joinType match {
case _: InnerLike | RightOuter => OutOfBoundsPolicy.DONT_CHECK
case _ => OutOfBoundsPolicy.NULLIFY
}
val lazyRightMap = LazySpillableGatherMap(right, "right_map")
val rightGatherer = JoinGatherer(lazyRightMap, rightData, rightOutOfBoundsPolicy)
MultiJoinGather(leftGatherer, rightGatherer)
}
if (gatherer.isDone) {
// Nothing matched...
gatherer.close()
None
} else {
Some(gatherer)
}
} finally {
maps.foreach(_.close())
}
}
}
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