{"record":{"id":"7132cd593cbe9d47","repo":"apache/seatunnel","slug":"redis-sink-cannot-restore-writer-for-table-s-beca","errorCode":null,"errorMessage":"Redis sink cannot restore writer for table %s because state 0 fields %s differ from state %d fields %s","messagePattern":"Redis sink cannot restore writer for table (.+?) because state 0 fields (.+?) differ from state (.+?) fields (.+?)","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"seatunnel-connectors-v2/connector-redis/src/main/java/org/apache/seatunnel/connectors/seatunnel/redis/sink/RedisSink.java","lineNumber":78,"sourceCode":"        return new RedisSinkWriter(tableSchema, redisParameters);\n    }\n\n    /**\n     * Restores the latest writer schema. Rescaling can provide state from multiple writers, and\n     * every state must contain the same schema because selecting the widest schema would restore a\n     * stale definition after a drop-column event.\n     */\n    @Override\n    public RedisSinkWriter restoreWriter(SinkWriter.Context context, List<TableSchema> states)\n            throws IOException {\n        if (states == null || states.isEmpty()) {\n            return createWriter(context);\n        }\n        TableSchema restoredSchema = states.get(0);\n        for (int stateIndex = 1; stateIndex < states.size(); stateIndex++) {\n            TableSchema state = states.get(stateIndex);\n            if (!restoredSchema.equals(state)) {\n                throw new IOException(\n                        String.format(\n                                \"Redis sink cannot restore writer for table %s because state 0 fields %s differ from state %d fields %s\",\n                                catalogTable.getTablePath().getFullName(),\n                                schemaFields(restoredSchema),\n                                stateIndex,\n                                schemaFields(state)));\n            }\n        }\n        return new RedisSinkWriter(restoredSchema, redisParameters);\n    }\n\n    @Override\n    public Optional<Serializer<TableSchema>> getWriterStateSerializer() {\n        return Optional.of(new DefaultSerializer<>());\n    }\n\n    @Override\n    public Optional<CatalogTable> getWriteCatalogTable() {","sourceCodeStart":60,"sourceCodeEnd":96,"githubUrl":"https://github.com/apache/seatunnel/blob/cf67b549a7a6c35fa0beb12d83c62892427ea919/seatunnel-connectors-v2/connector-redis/src/main/java/org/apache/seatunnel/connectors/seatunnel/redis/sink/RedisSink.java#L60-L96","documentation":"On job recovery, RedisSink.restoreWriter() compares the TableSchema of the first saved state against every other state; if any differ it throws an IOException explaining that a single writer cannot be restored from inconsistent table states. This guards against silently writing data with a mismatched schema after a savepoint/checkpoint restart or config change.","triggerScenarios":"restoreWriter() is called with multiple saved TableSchema states where state N (N>=1) does not equal state 0 — typically because the sink's catalog table schema (columns/types) was changed between the savepoint and the restore, producing divergent field lists.","commonSituations":"Altering column names/types in the SeaTunnel SQL/config and resuming from an old savepoint; multi-upstream pipelines whose branches produced different schemas; or version upgrades that changed schema serialization.","solutions":["Restore from a savepoint taken with the same table schema, or discard the old savepoint and start the job fresh (losing in-flight state).","Revert schema changes (column names/types/order) so they match the saved state exactly.","If schemas legitimately differ per branch, split into separate sink/table configurations instead of merging into one sink state.","Verify the restored schema by printing schemaFields of state 0 and the diverging state from the message and aligning them."],"exampleFix":"// before\n# schema changed: added column age\nschema = { fields { id int, name string, age int } }\n// after\n# match original schema, or start fresh without old savepoint\nschema = { fields { id int, name string } }","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try {\n    sink.restoreWriter(context, states);\n} catch (IOException e) {\n    // schema drift detected: align schema or discard old savepoint and restart\n}","preventionTips":["Don't change table schema between savepoint and restore","Keep per-branch schemas identical when sharing one sink","Version/save schema changes and match savepoints to schema versions"],"tags":["redis","sink","state-restore","schema-mismatch"],"backgroundTag":"schema-validation-failed","analyzedSha":"cf67b549a7a6c35fa0beb12d83c62892427ea919","analyzedAt":"2026-09-10T21:44:55.265Z","contentChangedAt":"2026-09-10T21:44:55.265Z","schemaVersion":2},"datasetVersion":"2026-09-14T11:17:12.474Z"}