[SOLR-17155] Groupby query reports null pointer when unique key is not stored

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 9.4.1
• Component/s: Grouping, query
• Assignee: Unassigned
• Reporter: rajanimaski
• Created: 07/Feb/24 15:48
• Updated: 04/Mar/24 18:11

Description

Group by query is failing with the following error message. It looks like TopGroupsResultTransformer.java  retrieveDocument method is fetching doc based on id is calling a stored field visitor method. I tried setting the "id" field to use doc values as they are enabled "useDocValuesAsStored:true" but this didn't help. 
 
 
Error message - 
java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null => java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null at org.apache.solr.schema.FieldType.toExternal(FieldType.java:378) java.lang.NullPointerException: Cannot invoke "org.apache.lucene.index.IndexableField.stringValue()" because "f" is null at org.apache.solr.schema.FieldType.toExternal(FieldType.java:378) ~[?:?] at org.apache.solr.search.grouping.distributed.shardresultserializer.TopGroupsResultTransformer.serializeTopGroups(TopGroupsResultTransformer.java:238) ~[?:?]