[
https://issues.apache.org/jira/browse/SPARK-19368?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ohad Raviv updated SPARK-19368:
-------------------------------
Description:
In SPARK-12869, this function was optimized for the case of dense matrices
using Breeze. However, I have a case with very very sparse matrices which
suffers a great deal from this optimization. A process we have that took about
20 mins now takes about 6.5 hours.
Here is a sample code to see the difference:
{quote}
val n = 40000
val density = 0.0002
val rnd = new Random(123)
val rndEntryList = (for (i <- 0 until (n*n*density).toInt) yield
(rnd.nextInt\(n\), rnd.nextInt\(n\), rnd.nextDouble()))
.groupBy(t => (t._1,t._2)).map\(t => t._2.last).map\{ case
(i,j,d) => (i,(j,d)) }.toSeq
val entries: RDD\[(Int, (Int, Double))] = sc.parallelize(rndEntryList, 10)
val indexedRows = entries.groupByKey().map(e => IndexedRow(e._1,
Vectors.sparse(n, e._2.toSeq)))
val mat = new IndexedRowMatrix(indexedRows, nRows = n, nCols = n)
val t1 = System.nanoTime()
println(mat.toBlockMatrix(10000,10000).toCoordinateMatrix().toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
val t2 = System.nanoTime()
println("took: " + (t2 - t1) / 1000 / 1000 + " ms")
println("============================================================")
println(mat.toBlockMatrix(10000,10000).toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
val t3 = System.nanoTime()
println("took: " + (t3 - t2) / 1000 / 1000 + " ms")
println("============================================================")
{quote}
I get:
{quote}
took: 9404 ms
============================================================
took: 57350 ms
============================================================
{quote}
Looking at it a little with a profiler, I see that the problem is with the
SliceVector.update() and SparseVector.apply.
I currently work-around this by doing:
{quote}
blockMatrix.toCoordinateMatrix().toIndexedRowMatrix()
{quote}
like it was in version 1.6.
was:
In SPARK-12869, this function was optimized for the case of dense matrices
using Breeze. However, I have a case with very very sparse matrices which
suffers a great deal from this optimization. A process we have that took about
20 mins now takes about 6.5 hours.
Here is a sample code to see the difference:
{quote}
val n = 40000
val density = 0.0002
val rnd = new Random(123)
val rndEntryList = (for (i <- 0 until (n*n*density).toInt) yield
(rnd.nextInt(n), rnd.nextInt(n), rnd.nextDouble()))
.groupBy(t => (t._1,t._2)).map(t => t._2.last).map { case
(i,j,d) => (i,(j,d)) }.toSeq
val entries: RDD[(Int, (Int, Double))] = sc.parallelize(rndEntryList, 10)
val indexedRows = entries.groupByKey().map(e => IndexedRow(e._1,
Vectors.sparse(n, e._2.toSeq)))
val mat = new IndexedRowMatrix(indexedRows, nRows = n, nCols = n)
val t1 = System.nanoTime()
println(mat.toBlockMatrix(10000,10000).toCoordinateMatrix().toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
val t2 = System.nanoTime()
println("took: " + (t2 - t1) / 1000 / 1000 + " ms")
println("============================================================")
println(mat.toBlockMatrix(10000,10000).toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
val t3 = System.nanoTime()
println("took: " + (t3 - t2) / 1000 / 1000 + " ms")
println("============================================================")
{quote}
I get:
{quote}
took: 9404 ms
============================================================
took: 57350 ms
============================================================
{quote}
Looking at it a little with a profiler, I see that the problem is with the
SliceVector.update() and SparseVector.apply.
I currently work-around this by doing:
BlockMatrix.toCoordinateMatrix().toIndexedRowMatrix()
like it was in the previous version.
> Very bad performance in BlockMatrix.toIndexedRowMatrix()
> --------------------------------------------------------
>
> Key: SPARK-19368
> URL: https://issues.apache.org/jira/browse/SPARK-19368
> Project: Spark
> Issue Type: Bug
> Components: MLlib
> Affects Versions: 2.0.0, 2.1.0
> Reporter: Ohad Raviv
>
> In SPARK-12869, this function was optimized for the case of dense matrices
> using Breeze. However, I have a case with very very sparse matrices which
> suffers a great deal from this optimization. A process we have that took
> about 20 mins now takes about 6.5 hours.
> Here is a sample code to see the difference:
> {quote}
> val n = 40000
> val density = 0.0002
> val rnd = new Random(123)
> val rndEntryList = (for (i <- 0 until (n*n*density).toInt) yield
> (rnd.nextInt\(n\), rnd.nextInt\(n\), rnd.nextDouble()))
> .groupBy(t => (t._1,t._2)).map\(t => t._2.last).map\{ case
> (i,j,d) => (i,(j,d)) }.toSeq
> val entries: RDD\[(Int, (Int, Double))] = sc.parallelize(rndEntryList, 10)
> val indexedRows = entries.groupByKey().map(e => IndexedRow(e._1,
> Vectors.sparse(n, e._2.toSeq)))
> val mat = new IndexedRowMatrix(indexedRows, nRows = n, nCols = n)
> val t1 = System.nanoTime()
>
> println(mat.toBlockMatrix(10000,10000).toCoordinateMatrix().toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
> val t2 = System.nanoTime()
> println("took: " + (t2 - t1) / 1000 / 1000 + " ms")
> println("============================================================")
>
> println(mat.toBlockMatrix(10000,10000).toIndexedRowMatrix().rows.map(_.vector.numActives).sum())
> val t3 = System.nanoTime()
> println("took: " + (t3 - t2) / 1000 / 1000 + " ms")
> println("============================================================")
> {quote}
> I get:
> {quote}
> took: 9404 ms
> ============================================================
> took: 57350 ms
> ============================================================
> {quote}
> Looking at it a little with a profiler, I see that the problem is with the
> SliceVector.update() and SparseVector.apply.
> I currently work-around this by doing:
> {quote}
> blockMatrix.toCoordinateMatrix().toIndexedRowMatrix()
> {quote}
> like it was in version 1.6.
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