From 647ee05e5815bde361662a9286ac602c44b4d4e6 Mon Sep 17 00:00:00 2001
From: codlife <1004910847@qq.com>
Date: Thu, 15 Sep 2016 09:38:13 +0100
Subject: [PATCH] [SPARK-17521] Error when I use sparkContext.makeRDD(Seq())
## What changes were proposed in this pull request?
when i use sc.makeRDD below
```
val data3 = sc.makeRDD(Seq())
println(data3.partitions.length)
```
I got an error:
Exception in thread "main" java.lang.IllegalArgumentException: Positive number of slices required
We can fix this bug just modify the last line ,do a check of seq.size
```
def makeRDD[T: ClassTag](seq: Seq[(T, Seq[String])]): RDD[T] = withScope {
assertNotStopped()
val indexToPrefs = seq.zipWithIndex.map(t => (t._2, t._1._2)).toMap
new ParallelCollectionRDD[T](this, seq.map(_._1), math.max(seq.size, defaultParallelism), indexToPrefs)
}
```
## How was this patch tested?
manual tests
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)
Author: codlife <1004910847@qq.com>
Author: codlife <wangjianfei15@otcaix.iscas.ac.cn>
Closes #15077 from codlife/master.
---
core/src/main/scala/org/apache/spark/SparkContext.scala | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/core/src/main/scala/org/apache/spark/SparkContext.scala b/core/src/main/scala/org/apache/spark/SparkContext.scala
index e32e4aa5b8..35b6334832 100644
--- a/core/src/main/scala/org/apache/spark/SparkContext.scala
+++ b/core/src/main/scala/org/apache/spark/SparkContext.scala
@@ -795,7 +795,7 @@ class SparkContext(config: SparkConf) extends Logging with ExecutorAllocationCli
def makeRDD[T: ClassTag](seq: Seq[(T, Seq[String])]): RDD[T] = withScope {
assertNotStopped()
val indexToPrefs = seq.zipWithIndex.map(t => (t._2, t._1._2)).toMap
- new ParallelCollectionRDD[T](this, seq.map(_._1), seq.size, indexToPrefs)
+ new ParallelCollectionRDD[T](this, seq.map(_._1), math.max(seq.size, 1), indexToPrefs)
}
/**
--
GitLab