用ftp读远程机器上的文件在Apache中星火 [英] Read file on remote machine in Apache Spark using ftp
问题描述
我想读取远程计算机上的Apache中的星火使用ftp文件(斯卡拉版)。目前,我已经遵循了GitHub上Databricks的学习星火回购的例子。使用curl,我可以下载的文件,所以我使用的路径存在。
I am trying to read a file on an remote machine in Apache Spark (the Scala version) using ftp. Currently, I have followed an example in the Learning Spark repo of Databricks on GitHub. Using curl, I am able to download the file, so the path I uses exists.
下面是code的片断我试图执行:
Below is a snippet of the code I try to execute:
var file = sc.textFile("ftp://user:pwd/192.168.1.5/brecht-d-m/map/input.nt")
var fileDF = file.toDF()
fileDF.write.parquet("out")
试图在数据框执行计数后,我获得以下堆栈跟踪( http://pastebin.com/YEq8c2Hf一>)
org.apache.spark.sql.catalyst.errors.package$TreeNodeException: execute, tree:
TungstenAggregate(key=[], functions=[(count(1),mode=Final,isDistinct=false)], output=[count#1L])
+- TungstenExchange SinglePartition, None
+- TungstenAggregate(key=[], functions=[(count(1),mode=Partial,isDistinct=false)], output=[count#4L])
+- Project
+- Scan ExistingRDD[_1#0]
...
Caused by: org.apache.hadoop.mapred.InvalidInputException: Input path does not exist: ftp://user:pwd@192.168.1.5/brecht-d-m/map/input.nt
我会假设该文件将无法访问,但这是在矛盾与我能够通过卷曲来检索文件:
I would assume that the file would be unreachable, but this is in contradiction with that I am able to retrieve the file via curl:
curl ftp://user:pwd@192.168.1.5/brecht-d-m/map/input.nt
这将打印出我的终端上的特定文件。我不明白我在做什么错在斯卡拉code。有没有在code段错误我给上面,或者是code完全错误的?
This will print out the specific file on my terminal. I do not see what I am doing wrong in the Scala code. Is there an error in the code snippet I gave above, or is that code totally wrong?
在此先感谢,
布莱希特
Thanks in advance, Brecht
请注意:
-
指定的完整路径(/home/brecht-dm/map/input.nt)也不起作用(如预期,因为这也是在袅袅不工作;服务器拒绝了你改变给定目录)。在星火尝试这一点,给了那些寻求不支持IOException异常( http://pastebin.com/b9EB9ru2 )。
在本地工作的(例如sc.textFile(/家庭/布莱希特-D-M /地图/ input.nt))完美的作品。
Working locally (e.g. sc.textFile("/home/brecht-d-m/map/input.nt")) works perfectly.
有关特定文件文件权限设置为R + W的所有用户。
File permissions for specific file is set to R+W for all users.
的文件大小(15MB)不应该是一个问题,它应该能够处理更大的文件
The file size (15MB) should not be a problem, and it should be able to handle much bigger files.
软件版本:斯卡拉2.11.7,阿帕奇星火1.6.0,Java的1.8.0_74的,Ubuntu 14.04.4
Software versions: Scala 2.11.7, Apache Spark 1.6.0, Java 1.8.0_74, Ubuntu 14.04.4
推荐答案
我能够找到一个解决办法。通过下面的codesnippet:
I was able to find a workaround. Via the codesnippet below:
import org.apache.spark.SparkFiles
val dataSource = "ftp://user:pwd/192.168.1.5/brecht-d-m/map/input.nt"
sc.addFile(dataSource)
var fileName = SparkFiles.get(dataSource.split("/").last)
var file = sc.textFile(fileName)
我能够下载FTP上的文件(使用相同的URL从第一code段)。此变通办法将首先下载文件(通过addFile)。接下来,我检索到的路径文件下载。最后,我使用的路径,文件加载到RDD。
I am able to download a file over FTP (with the same URL as from the first code snippet). This workaround will first download the file (via addFile). Next, I retrieve the path to where the file was downloaded. Finally, I use that path to load that file into an RDD.
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