{"record":{"id":"c1a9839028e322e9","repo":"apache/flink","slug":"unrecognized-type-s-this-method-is-deprecated-a","errorCode":null,"errorMessage":"Unrecognized type: %s. This method is deprecated and might not work for all supported types.","messagePattern":"Unrecognized type: (.+?)\\. This method is deprecated and might not work for all supported types\\.","errorType":"exception","errorClass":"IOException","httpStatus":null,"severity":"error","filePath":"flink-core/src/main/java/org/apache/flink/configuration/Configuration.java","lineNumber":581,"sourceCode":"                    case TYPE_LONG:\n                        value = in.readLong();\n                        break;\n                    case TYPE_FLOAT:\n                        value = in.readFloat();\n                        break;\n                    case TYPE_DOUBLE:\n                        value = in.readDouble();\n                        break;\n                    case TYPE_BOOLEAN:\n                        value = in.readBoolean();\n                        break;\n                    case TYPE_BYTES:\n                        byte[] bytes = new byte[in.readInt()];\n                        in.readFully(bytes);\n                        value = bytes;\n                        break;\n                    default:\n                        throw new IOException(\n                                String.format(\n                                        \"Unrecognized type: %s. This method is deprecated and\"\n                                                + \" might not work for all supported types.\",\n                                        type));\n                }\n\n                this.confData.put(key, value);\n            }\n        }\n    }\n\n    @Override\n    public void write(final DataOutputView out) throws IOException {\n        synchronized (this.confData) {\n            out.writeInt(this.confData.size());\n\n            for (Map.Entry<String, Object> entry : this.confData.entrySet()) {\n                String key = entry.getKey();","sourceCodeStart":563,"sourceCodeEnd":599,"githubUrl":"https://github.com/apache/flink/blob/2f3c205e9266cb30240eb7f4fdab15cad629a70f/flink-core/src/main/java/org/apache/flink/configuration/Configuration.java#L563-L599","documentation":"Configuration.readFields() rehydrates a Configuration from a Java DataInput using a per-entry type tag (TYPE_STRING/INT/LONG/DOUBLE/BOOLEAN/BYTES). If the stream contains a tag outside the known set, it throws IOException 'Unrecognized type: %s...' — the serialized form is corrupt or was written by an incompatible writer, so deserialization of the config cannot proceed.","triggerScenarios":"Reading a Configuration from a data stream produced by a different serialization version or truncated/corrupted in transit (RPC frames, checkpoint metadata holding an embedded Configuration); manually constructed DataInput fed to readFields; byte-array truncation before readFields.","commonSituations":"Corrupted RPC payload or checkpoint metadata; mixing incompatible Flink versions between sender and receiver of an embedded Configuration; rare — internal format evolution without version handshake.","solutions":["Ensure writer and reader run the same Flink version (this legacy format has no cross-version guarantees).","Verify integrity/size of the byte stream being handed to readFields before calling it.","If data came from a checkpoint, select an intact checkpoint or re-create the job state.","For programmatic use, prefer the modern Configuration serialization (ConfigurationUtils / flink-configuration YAML or the versioned delegate) instead of raw readFields."],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try {\n    conf.readFields(input);\n} catch (IOException e) {\n    if (e.getMessage() != null && e.getMessage().startsWith(\"Unrecognized type\")) {\n        // corrupt or version-mismatched stream: cannot recover, reject payload\n    }\n    throw e;\n}","preventionTips":["Pin writer and reader to the same Flink version for this legacy format.","Length-prefix and checksum embedded Configuration payloads on the wire.","Migrate to the current Configuration serialization utilities."],"tags":["configuration","deserialization","corruption","legacy-api","flink-core"],"backgroundTag":null,"analyzedSha":"2f3c205e9266cb30240eb7f4fdab15cad629a70f","analyzedAt":"2026-08-14T08:48:24.518Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}