Hi Marc,

yes, the deployMode was specified in the Gremlin Console and not in the properties file, as in the Tinkerpop example, so that's way it was not explicit here.
I am not sure why EMR would be limiting anything, since any different Spark application spawns more executors. But I am still investigating this, I will compare the entire properties list (which is reported in Spark UI as well), maybe there is something different.

For the output folder, yes it is working correctly in a way: I tried executing the CloneVertexProgram and it creates 768 files, all empty... and by zero I mean 0, while any other query (such as valueMap()) returns just nothing.

Best regards,
Alessandro