union replaces unionAll
The dataset and DataFrame API unionAll has been deprecated and replaced by union.
Type of change: Syntactic/Spark core change
Spark 1.6
unionAll is supported.
Spark 2.4
unionAll is deprecated and replaced by union.
Action Required
Replace unionAll with union. For example:val df3 = df.unionAll(df2)
with val
df3 = df.union(df2)