{"record":{"id":"a840a488861c6a1c","repo":"apache/hadoop","slug":"unsupported-credentials-flavor","errorCode":null,"errorMessage":"Unsupported Credentials Flavor ","messagePattern":"Unsupported Credentials Flavor ","errorType":"exception","errorClass":"UnsupportedOperationException","httpStatus":null,"severity":"error","filePath":"hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/oncrpc/security/Credentials.java","lineNumber":42,"sourceCode":"\n/**\n * Base class for all credentials. Currently we only support 3 different types\n * of auth flavors: AUTH_NONE, AUTH_SYS, and RPCSEC_GSS.\n */\npublic abstract class Credentials extends RpcAuthInfo {\n  public static final Logger LOG = LoggerFactory.getLogger(Credentials.class);\n\n  public static Credentials readFlavorAndCredentials(XDR xdr) {\n    AuthFlavor flavor = AuthFlavor.fromValue(xdr.readInt());\n    final Credentials credentials;\n    if(flavor == AuthFlavor.AUTH_NONE) {\n      credentials = new CredentialsNone();\n    } else if(flavor == AuthFlavor.AUTH_SYS) {\n      credentials = new CredentialsSys();\n    } else if(flavor == AuthFlavor.RPCSEC_GSS) {\n      credentials = new CredentialsGSS();\n    } else {\n      throw new UnsupportedOperationException(\"Unsupported Credentials Flavor \"\n          + flavor);\n    }\n    credentials.read(xdr);\n    return credentials;\n  }\n\n  /**\n   * Write AuthFlavor and the credentials to the XDR\n   * @param cred credentials\n   * @param xdr XDR message\n   */\n  public static void writeFlavorAndCredentials(Credentials cred, XDR xdr) {\n    if (cred instanceof CredentialsNone) {\n      xdr.writeInt(AuthFlavor.AUTH_NONE.getValue());\n    } else if (cred instanceof CredentialsSys) {\n      xdr.writeInt(AuthFlavor.AUTH_SYS.getValue());\n    } else if (cred instanceof CredentialsGSS) {\n      xdr.writeInt(AuthFlavor.RPCSEC_GSS.getValue());","sourceCodeStart":24,"sourceCodeEnd":60,"githubUrl":"https://github.com/apache/hadoop/blob/2add9630210752f88ceb1bb74eb65e37bf41da8e/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/oncrpc/security/Credentials.java#L24-L60","documentation":"Error \"Unsupported Credentials Flavor \" thrown in apache/hadoop.","triggerScenarios":"Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/oncrpc/security/Credentials.java:42 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Use a supported RPC credentials flavor (AUTH_NONE, AUTH_SYS/AUTH_UNIX, or RPCSEC_GSS as supported by the server).","Check the client configuration for the authentication flavor and correct unsupported or misspelled values.","Upgrade the client if it attempts to use a flavor this Hadoop version does not implement."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2add9630210752f88ceb1bb74eb65e37bf41da8e","analyzedAt":"2026-08-22T19:55:07.957Z","schemaVersion":2},"datasetVersion":"2026-08-23T01:17:44.959Z"}