{"record":{"id":"f791c92b1706847f","repo":"apache/druid","slug":"unsupported-single-value-version-s","errorCode":null,"errorMessage":"Unsupported single-value version[%s]","messagePattern":"Unsupported single-value version\\[(.+?)\\]","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"critical","filePath":"processing/src/main/java/org/apache/druid/segment/serde/DictionaryEncodedColumnPartSerde.java","lineNumber":432,"sourceCode":"            rSpatialIndex != null,\n            columnFormatSpec\n        ));\n      }\n\n      private WritableSupplier<ColumnarInts> readSingleValuedColumn(\n          VERSION version,\n          ByteBuffer buffer,\n          SegmentFileMapper fileMapper\n      )\n      {\n        switch (version) {\n          case UNCOMPRESSED_SINGLE_VALUE:\n          case UNCOMPRESSED_WITH_FLAGS:\n            return VSizeColumnarInts.readFromByteBuffer(buffer);\n          case COMPRESSED:\n            return CompressedVSizeColumnarIntsSupplier.fromByteBuffer(buffer, byteOrder, fileMapper);\n          default:\n            throw new IAE(\"Unsupported single-value version[%s]\", version);\n        }\n      }\n\n      private WritableSupplier<ColumnarMultiInts> readMultiValuedColumn(\n          VERSION version,\n          ByteBuffer buffer,\n          int flags,\n          SegmentFileMapper fileMapper\n      )\n      {\n        switch (version) {\n          case UNCOMPRESSED_MULTI_VALUE: {\n            return VSizeColumnarMultiInts.readFromByteBuffer(buffer);\n          }\n          case UNCOMPRESSED_WITH_FLAGS: {\n            if (Feature.MULTI_VALUE.isSet(flags)) {\n              return VSizeColumnarMultiInts.readFromByteBuffer(buffer);\n            } else {","sourceCodeStart":414,"sourceCodeEnd":450,"githubUrl":"https://github.com/apache/druid/blob/9b90983fd291f26935af934383ce360473179e4d/processing/src/main/java/org/apache/druid/segment/serde/DictionaryEncodedColumnPartSerde.java#L414-L450","documentation":"When deserializing a single-valued dictionary-encoded string column, DictionaryEncodedColumnPartSerde.read dispatches on the column's VERSION enum. If the version is not UNCOMPRESSED_SINGLE_VALUE, UNCOMPRESSED_WITH_FLAGS, or COMPRESSED, this IAE is thrown. The segment column was written with an unknown/incompatible format version.","triggerScenarios":"readSingleValuedColumn (invoked via read() during segment load) encountering a VERSION value outside the supported set — segment written by a newer Druid or corrupted version byte.","commonSituations":"Rolling back Druid to a version older than the one that wrote the segments; mixing cluster versions where a broker/historical reads segments from a newer writer; bit rot or truncated files corrupting the version field.","solutions":["Upgrade the historical/broker to a Druid version that can read the segment format (the version that wrote it).","Re-ingest the affected data with the current cluster version to rewrite segments in a supported format.","Restore corrupted segment files from deep storage.","Verify all cluster nodes run the same Druid version before loading shared segment stores."],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":"try {\n    cursor = adapter.makeCursors(filter, interval, virtualColumns, granularity, descending, queryMetrics);\n} catch (IAE e) {\n    if (e.getMessage().contains(\"Unsupported single-value version\")) {\n        log.error(\"Segment format unsupported; upgrade Druid or re-ingest segment %s\", segmentId);\n    }\n    throw e;\n}","preventionTips":["Align Druid versions across the cluster before rolling upgrades/downgrades.","Re-ingest legacy segments after major version upgrades if format support changes.","Verify segment integrity after bulk copies between storage tiers."],"tags":["druid","segment","version-mismatch","column","compatibility"],"backgroundTag":"unsupported-enum-value","analyzedSha":"9b90983fd291f26935af934383ce360473179e4d","analyzedAt":"2026-09-07T13:32:30.957Z","contentChangedAt":"2026-09-07T13:32:30.957Z","schemaVersion":2},"datasetVersion":"2026-09-14T11:17:12.474Z"}