Here’s test to try:
1) Install Kylo 0.8.3 nars
2) Change ‘Validate and Split Records’ processor and set SparkMaster to yarn-cluster (verify it works)
3) Upgrade to Kylo 0.8.4 nars
4) Verify if ‘Validate and Split Records’ still uses yarn-cluster (the default value for ‘Spark YARN Deploy Mode’ might cause an issue)
Should be fixed now. Please re-test.