在纱线集群上使用 addFile 和管道

Question

我已经成功地将 pyspark 与我的 YARN 集群结合使用。我正在做的工作涉及使用 RDD 的管道命令通过我制作的二进制文件发送数据。我可以在 pyspark 中轻松完成此操作，如下所示（假设“sc”已定义）：

sc.addFile("./dumb_prog") 
t= sc.parallelize(range(10))
t.pipe("dumb_prog")
t.take(10) # Gives expected result

但是，如果我在 Scala 中执行相同的操作，管道命令会收到“无法运行程序“dumb_prog”：错误=2，没有这样的文件或目录”错误。这是 Scala shell 中的代码：

sc.addFile("./dumb_prog")
val t = sc.parallelize(0 until 10)
val u = t.pipe("dumb_prog")
u.take(10)

为什么这只能在 Python 中工作，而不能在 Scala 中工作？有什么办法可以让它在 Scala 中工作吗？

以下是来自 scala 端的完整错误消息：

[59/3965]
14/09/29 13:07:47 INFO SparkContext: Starting job: take at <console>:17
14/09/29 13:07:47 INFO DAGScheduler: Got job 3 (take at <console>:17) with 1
output partitions (allowLocal=true)
14/09/29 13:07:47 INFO DAGScheduler: Final stage: Stage 3(take at
<console>:17)
14/09/29 13:07:47 INFO DAGScheduler: Parents of final stage: List()
14/09/29 13:07:47 INFO DAGScheduler: Missing parents: List()
14/09/29 13:07:47 INFO DAGScheduler: Submitting Stage 3 (PipedRDD[3] at pipe
at <console>:14), which has no missing parents
14/09/29 13:07:47 INFO MemoryStore: ensureFreeSpace(2136) called with
curMem=7453, maxMem=278302556
14/09/29 13:07:47 INFO MemoryStore: Block broadcast_3 stored as values in
memory (estimated size 2.1 KB, free 265.4 MB)
14/09/29 13:07:47 INFO MemoryStore: ensureFreeSpace(1389) called with
curMem=9589, maxMem=278302556
14/09/29 13:07:47 INFO MemoryStore: Block broadcast_3_piece0 stored as bytes
in memory (estimated size 1389.0 B, free 265.4 MB)
14/09/29 13:07:47 INFO BlockManagerInfo: Added broadcast_3_piece0 in memory
on 10.10.0.20:37574 (size: 1389.0 B, free: 265.4 MB)
14/09/29 13:07:47 INFO BlockManagerMaster: Updated info of block
broadcast_3_piece0
14/09/29 13:07:47 INFO DAGScheduler: Submitting 1 missing tasks from Stage 3
(PipedRDD[3] at pipe at <console>:14)
14/09/29 13:07:47 INFO YarnClientClusterScheduler: Adding task set 3.0 with
1 tasks
14/09/29 13:07:47 INFO TaskSetManager: Starting task 0.0 in stage 3.0 (TID
6, SERVERNAME, PROCESS_LOCAL, 1201 bytes)
14/09/29 13:07:47 INFO BlockManagerInfo: Added broadcast_3_piece0 in memory
on SERVERNAME:57118 (size: 1389.0 B, free: 530.3 MB)
14/09/29 13:07:47 WARN TaskSetManager: Lost task 0.0 in stage 3.0 (TID 6,
SERVERNAME): java.io.IOException: Cannot run program "dumb_prog": error=2,
No such file or directory
    java.lang.ProcessBuilder.start(ProcessBuilder.java:1041)
    org.apache.spark.rdd.PipedRDD.compute(PipedRDD.scala:119)
    org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262)
    org.apache.spark.rdd.RDD.iterator(RDD.scala:229)
    org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:62)
    org.apache.spark.scheduler.Task.run(Task.scala:54)

Answer 1

我在 Spark 1.3.0 的 Yarn 客户端模式下遇到了类似的问题。当我查看应用程序缓存目录时，即使使用--files. 但是当我添加以下内容时，它确实推送到每个执行程序：

sc.addFile("dumb_prog",true)
t.pipe("./dumb_prog")

我认为这是一个错误，但上面的内容让我解决了这个问题。