We can set Parquet blockSize, pageSize and dictionary pageSize to any value. It uses LongValidator which is not exactly validating the value. Since all these sizes are used as int in the code, even though user is able to set them to any value (could be greater than MAXINT and/or negative), parsing the value later in the code as int can throw an error. Instead, restrict the value that can be set to MAXINT.
There is a bug open for validating system/session options in general. https://issues.apache.org/jira/browse/DRILL-2478