ModuleNotFoundError because PySpark serializer is not able to locate library folder

问题

I have the following folder structure

 - libfolder
    - lib1.py
    - lib2.py
 - main.py

main.py calls libfolder.lib1.py which then calls libfolder.lib2.py and others.

It all works perfectly fine in local machine but after I deploy it to Dataproc I get the following error

File "/usr/lib/spark/python/lib/pyspark.zip/pyspark/serializers.py", line 455, in loads
return pickle.loads(obj, encoding=encoding)
ModuleNotFoundError: No module named 'libfolder'

I have zipped the folder into xyz.zip and run the following command:

spark-submit --py-files=xyz.zip main.py

The serializer is not able to find the location for libfolder . Is there a problem with the way i am packaging my folders?

This issue is similar to this one but it's not answered.

Edit: response to Igor's questions

unzip -l for the zip file returns the following

 - libfolder
    - lib1.py
    - lib2.py
 - main.py

In main.py lib1.py is called with this import statement

from libfolder import lib1

回答1:

This worked for me:

$ cat main.py

from pyspark import SparkContext, SparkConf

from subpkg import sub

conf = SparkConf().setAppName("Shell Count")
sc = SparkContext(conf = conf)

text_file = sc.textFile("file:///etc/passwd")
counts = text_file.map(lambda line: sub.map(line)) \
    .map(lambda shell: (shell, 1)) \
    .reduceByKey(lambda a, b: sub.reduce(a, b))

counts.saveAsTextFile("hdfs:///count5.txt")

$ cat subpkg/sub.py

def map(line):
  return line.split(":")[6]

def reduce(a, b):
  return a + b

$ unzip -l /tmp/deps.zip 
Archive:  /tmp/deps.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  2019-01-07 14:22   subpkg/
        0  2019-01-07 13:51   subpkg/__init__.py
       79  2019-01-07 14:13   subpkg/sub.py
---------                     -------
       79                     3 files


$ gcloud dataproc jobs submit pyspark --cluster test-cluster main.py --py-files deps.zip
Job [1f0f15108a4149c5942f49513ce04440] submitted.
Waiting for job output...
Hello world!
Job [1f0f15108a4149c5942f49513ce04440] finished successfully.

回答2:

For me works writing the py-files in quote.

spark2-submit --master yarn --verbose --deploy-mode client --py-files "dependencies.zip" $HOME/jobs/master/etl_master.py

Also remember the order of the arguments, I would recommend first to add --verbose after that submit again the job and look at the log to find the arguments your program is passing thought the server.

来源：https://stackoverflow.com/questions/53863576/modulenotfounderror-because-pyspark-serializer-is-not-able-to-locate-library-fol

标签

python

apache-spark

pyspark

google-cloud-dataproc