NPE during segment commit

[noob-se7en]

java.lang.NullPointerException: Cannot invoke "java.util.List.contains(Object)" because the return value of "org.apache.pinot.spi.config.table.PauseState.getIndexOfInactiveTopics()" is null
	at org.apache.pinot.controller.helix.core.realtime.PinotLLCRealtimeSegmentManager.isTopicPaused(PinotLLCRealtimeSegmentManager.java:1409)
	at org.apache.pinot.controller.helix.core.realtime.PinotLLCRealtimeSegmentManager.isTopicPaused(PinotLLCRealtimeSegmentManager.java:1417)
	at org.apache.pinot.controller.helix.core.realtime.PinotLLCRealtimeSegmentManager.createNewSegmentMetadata(PinotLLCRealtimeSegmentManager.java:785)
	at org.apache.pinot.controller.helix.core.realtime.PinotLLCRealtimeSegmentManager.commitSegmentMetadataInternal(PinotLLCRealtimeSegmentManager.java:659)
	at org.apache.pinot.controller.helix.core.realtime.PinotLLCRealtimeSegmentManager.commitSegmentMetadata(PinotLLCRealtimeSegmentManager.java:623)
	at org.apache.pinot.controller.helix.core.realtime.BlockingSegmentCompletionFSM.commitSegmentMetadata(BlockingSegmentCompletionFSM.java:844)
	at org.apache.pinot.controller.helix.core.realtime.BlockingSegmentCompletionFSM.commitSegment(BlockingSegmentCompletionFSM.java:829)
	at org.apache.pinot.controller.helix.core.realtime.BlockingSegmentCompletionFSM.segmentCommitEnd(BlockingSegmentCompletionFSM.java:388)
	at org.apache.pinot.controller.helix.core.realtime.SegmentCompletionManager.segmentCommitEnd(SegmentCompletionManager.java:322)
	at org.apache.pinot.controller.api.resources.LLCSegmentCompletionHandlers.segmentCommitEndWithMetadata(LLCSegmentCompletionHandlers.java:303)

Looks like these errors are due to #16692

@lnbest0707-uber @chenboat can you check this and help with unit tests/integrations tests for covering the new code
Seems like a backward incompatible change.

[lnbest0707]

@noob-se7en thanks for sharing the issue. Actually I cannot get this reproduced in my env (cannot find this in our logs). The object setter has already dealt with the null input.

public void setIndexOfInactiveTopics(List<Integer> indexOfInactiveTopics) {
    _indexOfInactiveTopics = indexOfInactiveTopics == null ? new ArrayList<>() : indexOfInactiveTopics;
  }

Could you pls share how this got triggered? Thanks

Edit: Possibly due to the empty constructor public PauseState() {}, will fix it in a PR.

[noob-se7en]

Yeah it's due to empty constructor. Below unit test can reproduce it:

String pauseStateStr = "{\"reasonCode\":\"ADMINISTRATIVE\",\"paused\":false,\"timeInMillis\":\"2025-07-21 06:30:40.709\"}";
PauseState pauseState = JsonUtils.stringToObject(pauseStateStr, PauseState.class);
boolean contains = pauseState.getIndexOfInactiveTopics().contains(0); // NPE as list will be null