Glue AWS: error occurred while calling o60.getDynamicFrame

Question

I have defined a basic script to create a DF with data coming from one of my tables in redshift. I run the process but I have been struggling for a while with a message that I'm not able to interpret.

The error output in the log is:

"/mnt/yarn/usercache/root/appcache/application_1525803778049_0004/container_1525803778049_0004_01_000001/py4j-0.10.4-src.zip/py4j/protocol.py", line 319, in get_return_value py4j.protocol.Py4JJavaError: An error occurred while calling o60.getDynamicFrame. : java.lang.UnsupportedOperationException: empty.reduceLeft at scala.collection.

import sys
from awsglue.transforms import *
from awsglue.utils import getResolvedOptions
from pyspark.context import SparkContext
from awsglue.context import GlueContext
from awsglue.dynamicframe import DynamicFrame, DynamicFrameReader, DynamicFrameWriter, DynamicFrameCollection
from pyspark.sql.functions import lit
from awsglue.job import Job

sc = SparkContext()
glueContext = GlueContext(sc)
spark = glueContext.spark_session
job = Job(glueContext)

table = glueContext.create_dynamic_frame.from_options(connection_type="redshift", connection_options = 
    {"url": "jdbc:redshift://xxxxx.yyyyy.us-east-1.redshift.amazonaws.com:5439/db",
    "user": "yyyy",
    "password": "yyyyy",
    "dbtable": "schema.table_name",
    "redshiftTmpDir": "s3://aws-glue-temporary-accountnumber-us-east-1/"},
    format="orc", 
    transformation_ctx="table" )

table.show()

dfred = table.toDF().createOrReplaceTempView("table_df")

job.commit()

Please I appreciate any help that you can offer me. Thanks so much

Answer 1

Well, after keep on struggling with this I went thru the official code class for DynamicFrame So, I added in my code an apply format transformation to map the result coming from the read table in redshift and the method that pulls out the table I skip out the parameter transformation_ctx that was the one was failing in the error o60

My final version code is:

import sys
from awsglue.transforms import *
from awsglue.utils import getResolvedOptions
from pyspark.context import SparkContext
from awsglue.context import GlueContext
from awsglue.dynamicframe import DynamicFrame, DynamicFrameReader, DynamicFrameWriter, DynamicFrameCollection
from pyspark.sql.functions import lit
from awsglue.job import Job

sc = SparkContext()
glueContext = GlueContext(sc)
spark = glueContext.spark_session
job = Job(glueContext)

table = glueContext.create_dynamic_frame.from_options(connection_type="redshift", connection_options = 
    {"url": "jdbc:redshift://xxxxx.yyyyy.us-east-1.redshift.amazonaws.com:5439/db",
    "user": "yyyy",
    "password": "yyyyy",
    "dbtable": "schema.table_name",
    "redshiftTmpDir": "s3://aws-glue-temporary-accountnumber-us-east-1/"}
     )

applyformat = ApplyMapping.apply(frame =table, mappings =
    [("field1","string","field1","string"),
    ("field2","string","field2","string") ], transformation_ctx = "applyformat")    


dfred = table.toDF().createOrReplaceTempView("table_df")

sqlDF = spark.sql(
    "SELECT COUNT(*) FROM table_df"
    )


print sqlDF.show()

job.commit()