从 PySpark 连接到 S3 数据

Connect to S3 data from PySpark

我正在尝试从 Amazon s3 读取一个 JSON 文件,以创建一个 spark 上下文并使用它来处理数据。

Spark 基本上位于 docker 容器中。所以将文件放在 docker 路径中也是 PITA。因此将其推到 S3。

下面的代码解释了其余的内容。

from pyspark import SparkContext, SparkConf
conf = SparkConf().setAppName("first")
sc = SparkContext(conf=conf)

config_dict = {"fs.s3n.awsAccessKeyId":"**",
               "fs.s3n.awsSecretAccessKey":"**"}

bucket = "nonamecpp"
prefix = "dataset.json"
filename = "s3n://{}/{}".format(bucket, prefix)
rdd = sc.hadoopFile(filename,
                    'org.apache.hadoop.mapred.TextInputFormat',
                    'org.apache.hadoop.io.Text',
                    'org.apache.hadoop.io.LongWritable',
                    conf=config_dict)

我收到以下错误 -

Py4JJavaError                             Traceback (most recent call last)
<ipython-input-2-b94543fb0e8e> in <module>()
      9                     'org.apache.hadoop.io.Text',
     10                     'org.apache.hadoop.io.LongWritable',
---> 11                     conf=config_dict)
     12 

/usr/local/spark/python/pyspark/context.pyc in hadoopFile(self, path, inputFormatClass, keyClass, valueClass, keyConverter, valueConverter, conf, batchSize)
    558         jrdd = self._jvm.PythonRDD.hadoopFile(self._jsc, path, inputFormatClass, keyClass,
    559                                               valueClass, keyConverter, valueConverter,
--> 560                                               jconf, batchSize)
    561         return RDD(jrdd, self)
    562 

/usr/local/lib/python2.7/dist-packages/py4j/java_gateway.pyc in __call__(self, *args)
    536         answer = self.gateway_client.send_command(command)
    537         return_value = get_return_value(answer, self.gateway_client,
--> 538                 self.target_id, self.name)
    539 
    540         for temp_arg in temp_args:

/usr/local/lib/python2.7/dist-packages/py4j/protocol.pyc in get_return_value(answer, gateway_client, target_id, name)
    298                 raise Py4JJavaError(
    299                     'An error occurred while calling {0}{1}{2}.\n'.
--> 300                     format(target_id, '.', name), value)
    301             else:
    302                 raise Py4JError(

Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.hadoopFile.
: java.lang.IllegalArgumentException: AWS Access Key ID and Secret Access Key must be specified as the username or password (respectively) of a s3n URL, or by setting the fs.s3n.awsAccessKeyId or fs.s3n.awsSecretAccessKey properties (respectively).
    at org.apache.hadoop.fs.s3.S3Credentials.initialize(S3Credentials.java:70)
    at org.apache.hadoop.fs.s3native.Jets3tNativeFileSystemStore.initialize(Jets3tNativeFileSystemStore.java:73)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:190)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:103)
    at org.apache.hadoop.fs.s3native.$Proxy20.initialize(Unknown Source)
    at org.apache.hadoop.fs.s3native.NativeS3FileSystem.initialize(NativeS3FileSystem.java:272)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2397)
    at org.apache.hadoop.fs.FileSystem.access0(FileSystem.java:89)
    at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2431)
    at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2413)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:368)
    at org.apache.hadoop.fs.Path.getFileSystem(Path.java:296)
    at org.apache.hadoop.mapred.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:256)
    at org.apache.hadoop.mapred.FileInputFormat.listStatus(FileInputFormat.java:228)
    at org.apache.hadoop.mapred.FileInputFormat.getSplits(FileInputFormat.java:304)
    at org.apache.spark.rdd.HadoopRDD.getPartitions(HadoopRDD.scala:201)
    at org.apache.spark.rdd.RDD$$anonfun$partitions.apply(RDD.scala:205)
    at org.apache.spark.rdd.RDD$$anonfun$partitions.apply(RDD.scala:203)
    at scala.Option.getOrElse(Option.scala:120)
    at org.apache.spark.rdd.RDD.partitions(RDD.scala:203)
    at org.apache.spark.rdd.MappedRDD.getPartitions(MappedRDD.scala:28)
    at org.apache.spark.rdd.RDD$$anonfun$partitions.apply(RDD.scala:205)
    at org.apache.spark.rdd.RDD$$anonfun$partitions.apply(RDD.scala:203)
    at scala.Option.getOrElse(Option.scala:120)
    at org.apache.spark.rdd.RDD.partitions(RDD.scala:203)
    at org.apache.spark.rdd.RDD.take(RDD.scala:1060)
    at org.apache.spark.rdd.RDD.first(RDD.scala:1093)
    at org.apache.spark.api.python.SerDeUtil$.pairRDDToPython(SerDeUtil.scala:202)
    at org.apache.spark.api.python.PythonRDD$.hadoopFile(PythonRDD.scala:543)
    at org.apache.spark.api.python.PythonRDD.hadoopFile(PythonRDD.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
    at py4j.Gateway.invoke(Gateway.java:259)
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
    at py4j.commands.CallCommand.execute(CallCommand.java:79)
    at py4j.GatewayConnection.run(GatewayConnection.java:207)
    at java.lang.Thread.run(Thread.java:744)

我已经明确提供了aswSecretAccessKey和awsAccessId。怎么了?

我已经解决了将 --packages org.apache.hadoop:hadoop-aws:2.7.1 添加到 spark-submit 命令中的问题。

它将下载所有 hadoop 缺少的包,这些包将允许您使用 S3 执行 spark 作业。

然后在您的工作中,您需要设置您的 AWS 凭证,例如:

sc._jsc.hadoopConfiguration().set("fs.s3n.awsAccessKeyId", aws_id)
sc._jsc.hadoopConfiguration().set("fs.s3n.awsSecretAccessKey", aws_key)

关于设置凭据的其他选项是将它们定义到 spark/conf/spark-env:

#!/usr/bin/env bash
AWS_ACCESS_KEY_ID='xxxx'
AWS_SECRET_ACCESS_KEY='xxxx'

SPARK_WORKER_CORES=1 # to set the number of cores to use on this machine
SPARK_WORKER_MEMORY=1g # to set how much total memory workers have to give executors (e.g. 1000m, 2g)
SPARK_EXECUTOR_INSTANCES=10 #, to set the number of worker processes per node

更多信息:

我建议完成此 link

就我而言,我使用 实例配置文件凭据 访问 s3 数据。

Instance profile credentials– used on EC2 instances, and delivered through the Amazon EC2 metadata service. The AWS SDK for Java uses the InstanceProfileCredentialsProvider to load these credentials.

Note

Instance profile credentials are used only if AWS_CONTAINER_CREDENTIALS_RELATIVE_URI is not set. See EC2ContainerCredentialsProviderWrapper for more information.

对于 pyspark,我使用设置来访问 s3 内容。

def get_spark_context(app_name):
    # configure
    conf = pyspark.SparkConf()

    # init & return
    sc = pyspark.SparkContext.getOrCreate(conf=conf)

    # s3a config
    sc._jsc.hadoopConfiguration().set('fs.s3a.endpoint',
                                      's3.eu-central-1.amazonaws.com')
    sc._jsc.hadoopConfiguration().set(
        'fs.s3a.aws.credentials.provider',
        'com.amazonaws.auth.InstanceProfileCredentialsProvider,'
        'com.amazonaws.auth.profile.ProfileCredentialsProvider'
    )

    return pyspark.SQLContext(sparkContext=sc)

有关 spark 上下文的更多信息

请参阅 S3 类型访问。