{"record":{"id":"0ef9dba8b3579d59","repo":"apache/cassandra","slug":"mismatch-query","errorCode":null,"errorMessage":"{} - MISMATCH Query = {} ","messagePattern":"(.+?) - MISMATCH Query = (.+?) ","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"tools/fqltool/src/org/apache/cassandra/fqltool/ResultComparator.java","lineNumber":104,"sourceCode":"            if (!refDefs.equals(toCompare))\n                equal = false;\n        }\n        if (!equal)\n            handleColumnDefMismatch(targetHosts, query, cds);\n        return equal;\n    }\n\n    private void handleMismatch(List<String> targetHosts, FQLQuery query, List<ResultHandler.ComparableRow> rows)\n    {\n        UUID mismatchUUID = UUID.randomUUID();\n        StringBuilder sb = new StringBuilder(\"{} - MISMATCH Query = {} \");\n        for (int i = 0; i < targetHosts.size(); i++)\n            sb.append(\"mismatch\").append(i)\n              .append('=')\n              .append('\"').append(targetHosts.get(i)).append(':').append(rows.get(i)).append('\"')\n              .append(',');\n\n        logger.warn(sb.toString(), mismatchUUID, query);\n        try\n        {\n            if (mismatchListener != null)\n                mismatchListener.mismatch(mismatchUUID, targetHosts, query, rows);\n        }\n        catch (Throwable t)\n        {\n            logger.error(\"ERROR notifying listener\", t);\n        }\n    }\n\n    private void handleColumnDefMismatch(List<String> targetHosts, FQLQuery query, List<ResultHandler.ComparableColumnDefinitions> cds)\n    {\n        UUID mismatchUUID = UUID.randomUUID();\n        StringBuilder sb = new StringBuilder(\"{} - COLUMN DEFINITION MISMATCH Query = {} \");\n        for (int i = 0; i < targetHosts.size(); i++)\n            sb.append(\"mismatch\").append(i)\n              .append('=')","sourceCodeStart":86,"sourceCodeEnd":122,"githubUrl":"https://github.com/apache/cassandra/blob/88fd0f6a0eaed8943f05ac9e8f947882b8ddc8f1/tools/fqltool/src/org/apache/cassandra/fqltool/ResultComparator.java#L86-L122","documentation":"ResultComparator.handleMismatch in fqltool detected that rows returned for the same FQL query differ across compared clusters (e.g. in a migration/upgrade comparison run). The mismatch details are logged with a random UUID that is also passed to the mismatch listener for result dumps.","triggerScenarios":"Thrown at tools/fqltool/src/org/apache/cassandra/fqltool/ResultComparator.java:104 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Inspect the saved result files referenced by the mismatch UUID to find the differing rows.","Investigate schema/version differences or data drift between the compared clusters.","Re-run repair or fix the divergent data on the target cluster."],"exampleFix":null,"handlingStrategy":"fallback","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"88fd0f6a0eaed8943f05ac9e8f947882b8ddc8f1","analyzedAt":"2026-09-10T07:29:22.284Z","contentChangedAt":"2026-09-10T07:29:22.284Z","schemaVersion":2},"datasetVersion":"2026-09-17T15:17:12.973Z"}