在python3的互動式視窗中，引入pyspark包，并創建SparkSession，就可以用spark.read.csv("csv path")讀取一個 csv格式的檔案，但是，如果是hdfs格式的csv檔案卻不行，報錯：py4j.protocol.Py4JJavaError: An error occurred while calling o40.csv.
看了一下python官網，有其他的方式可以讀取hdfs檔案。為什么spark.read.csv("csv path") 這種方式不行呢？
附：完整錯誤資訊：
WARN FileStreamSink: Error while looking for metadata directory.
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python3.5/dist-packages/pyspark/sql/readwriter.py", line 476, in csv
return self._df(self._jreader.csv(self._spark._sc._jvm.PythonUtils.toSeq(path)))
File "/usr/local/lib/python3.5/dist-packages/py4j/java_gateway.py", line 1257, in __call__
answer, self.gateway_client, self.target_id, self.name)
File "/usr/local/lib/python3.5/dist-packages/pyspark/sql/utils.py", line 63, in deco
return f(*a, **kw)
File "/usr/local/lib/python3.5/dist-packages/py4j/protocol.py", line 328, in get_return_value
format(target_id, ".", name), value)
py4j.protocol.Py4JJavaError: An error occurred while calling o40.csv.
: java.io.IOException: Incomplete HDFS URI, no host: hdfs:///agriculture/historyClimate/59855.csv
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:143)
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2669)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)
at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)
at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$org$apache$spark$sql$execution$datasources$DataSource$$checkAndGlobPathIfNecessary$1.apply(DataSource.scala:547)
at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$org$apache$spark$sql$execution$datasources$DataSource$$checkAndGlobPathIfNecessary$1.apply(DataSource.scala:545)
at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:241)
at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:241)
at scala.collection.immutable.List.foreach(List.scala:392)
at scala.collection.TraversableLike$class.flatMap(TraversableLike.scala:241)
at scala.collection.immutable.List.flatMap(List.scala:355)
at org.apache.spark.sql.execution.datasources.DataSource.org$apache$spark$sql$execution$datasources$DataSource$$checkAndGlobPathIfNecessary(DataSource.scala:545)
at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:359)
at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:223)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:211)
at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:618)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
uj5u.com熱心網友回復：
這個問題解決了。在給csv_path賦值的時候，加上ip和埠號。比如：csv_path='hdfs://X.X.X.X:8020/a/b/c.csv'. 謝謝大家！轉載請註明出處，本文鏈接：https://www.uj5u.com/qita/23897.html
標籤：Spark
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