Github user ravipesala commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2521#discussion_r203603034
--- Diff:
processing/src/main/java/org/apache/carbondata/processing/loading/steps/DataWriterProcessorStepImpl.java
---
@@ -80,6 +85,7 @@ public
DataWriterProcessorStepImpl(CarbonDataLoadConfiguration configuration) {
@Override public void initialize() throws IOException {
super.initialize();
child.initialize();
+ this.carbonFactHandlers = new CopyOnWriteArrayList<>();
--- End diff --
Please do similar handing for `DataWriterBatchProcessorStepImpl` as well
---
