Problems when writing parquet with timestamps prior to 1900 in AWS Glue 3.0

Question

When switching from Glue 2.0 to 3.0, which means also switching from Spark 2.4 to 3.1.1, my jobs start to fail when processing timestamps prior to 1900 with this error:

An error occurred while calling z:org.apache.spark.api.python.PythonRDD.runJob.
You may get a different result due to the upgrading of Spark 3.0: reading dates before 1582-10-15 or timestamps before 1900-01-01T00:00:00Z from Parquet INT96 files can be ambiguous, 
as the files may be written by Spark 2.x or legacy versions of Hive, which uses a legacy hybrid calendar that is different from Spark 3.0+s Proleptic Gregorian calendar.
See more details in SPARK-31404.
You can set spark.sql.legacy.parquet.int96RebaseModeInRead to 'LEGACY' to rebase the datetime values w.r.t. the calendar difference during reading. 
Or set spark.sql.legacy.parquet.int96RebaseModeInRead to 'CORRECTED' to read the datetime values as it is.

I tried everything to set the int96RebaseModeInRead config in Glue, even contacted the Support, but it seems that currently Glue is overwriting that flag and you can not set it yourself.

If anyone knows a workaround, that would be great. Otherwise I will continue with Glue 2.0. and wait for the Glue dev team to fix this.

Answer 1

I made it work by setting --conf to spark.sql.legacy.parquet.int96RebaseModeInRead=CORRECTED --conf spark.sql.legacy.parquet.int96RebaseModeInWrite=CORRECTED --conf spark.sql.legacy.parquet.datetimeRebaseModeInRead=CORRECTED --conf spark.sql.legacy.parquet.datetimeRebaseModeInWrite=CORRECTED.

This is a workaround though and Glue Dev team is working on a fix, although there is no ETA.

Also this is still very buggy. You can not call .show() on a DynamicFrame for example, you need to call it on a DataFrame. Also all my jobs failed where I call data_frame.rdd.isEmpty(), don't ask me why.

Update 24.11.2021: I reached out to the Glue Dev Team and they told me that this is the intended way of fixing it. There is a workaround that can be done inside of the script though:

sc = SparkContext()
# Get current sparkconf which is set by glue
conf = sc.getConf()
# add additional spark configurations
conf.set("spark.sql.legacy.parquet.int96RebaseModeInRead", "CORRECTED")
conf.set("spark.sql.legacy.parquet.int96RebaseModeInWrite", "CORRECTED")
conf.set("spark.sql.legacy.parquet.datetimeRebaseModeInRead", "CORRECTED")
conf.set("spark.sql.legacy.parquet.datetimeRebaseModeInWrite", "CORRECTED")
# Restart spark context
sc.stop()
sc = SparkContext.getOrCreate(conf=conf)
# create glue context with the restarted sc
glueContext = GlueContext(sc)

Answer 2

The issue being addressed in the official Glue Developer guide

Migrating from AWS Glue 2.0 to AWS Glue 3.0 last bullet item.