MyCATApache/Mycat-Server · critical · RuntimeException

${e}

Error message

${e}

What it means

querySecurePath runs 'show variables like secure_file_priv' to discover where MySQL permits LOAD DATA/SELECT INTO OUTFILE files. A SQLException during the connection or query is rethrown as a RuntimeException, failing the dump runner before migration can proceed.

Solutions

1. Check config.getUrl(), user and password resolve to a reachable MySQL server.
2. Confirm the server supports secure_file_priv (MySQL >= 5.7.6); check with SHOW VARIABLES LIKE 'secure_file_priv'.
3. Inspect the wrapped SQLException in the stack trace for the root cause (timeout, access denied, unknown host).
4. If the variable is absent on your server, set a path manually or upgrade MySQL so OUTFILE-based transfer works.

Example fix

// before
con = DriverManager.getConnection("jdbc:mysql://" + config.getUrl(), config.getUser(), config.getPassword());
// after
try (Connection con = DriverManager.getConnection("jdbc:mysql://" + config.getUrl(), config.getUser(), config.getPassword())) {
    // wrap the RuntimeException with context
} catch (SQLException e) {
    throw new RuntimeException("Failed to query secure_file_priv from " + config.getUrl(), e);
}

// before running dump
Class.forName("com.mysql.jdbc.Driver");
try (Connection c = DriverManager.getConnection("jdbc:mysql://" + config.getUrl(), config.getUser(), config.getPassword())) {
    ResultSet rs = c.createStatement().executeQuery("SHOW VARIABLES LIKE 'secure_file_priv'");
    if (!rs.next()) throw new IllegalStateException("secure_file_priv unsupported/absent");
}

try { spath(); } catch (RuntimeException e) {
    if (e.getCause() instanceof java.sql.SQLException sql) {
        // log sql.getErrorCode()/getSQLState(), decide retry vs abort
    }
    throw e;
}

When it happens

Trigger: DriverManager.getConnection(config.getUrl()) fails (bad URL, auth, network); 'show variables like secure_file_priv' is rejected or the connection drops; the result set lacks the expected 'Value' row.

Common situations: MySQL 5.6- and MariaDB without the secure_file_priv variable (list is empty, path stays null and later file operations fail); wrong JDBC URL in config; the migration user cannot execute SHOW VARIABLES.

Understand the failure class

Background: Database query failed: Internal Server Error 500s wrapping SQL, Prisma, and connection failures — what to check first — this error's family across 16 libraries.

Related errors

• ${e}
• global seq and share join and special…
• fetching sequence can not support the db driver
• CallableStatement not supported
• Unexpected exception

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/6e6dcddfddf19490. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/migrate/MigrateDumpRunner.java:220

            } else {
                whereList.add("(_slot >=" + slotRange.start + " and _slot <=" + slotRange.end + ")");
            }
        }

        return Joiner.on(" or  ").join(whereList);
    }

    private static String querySecurePath(DBHostConfig config) {
        List<Map<String, Object>> list = null;
        String path = null;
        Connection con = null;
        try {
            con = DriverManager.getConnection("jdbc:mysql://" + config.getUrl(), config.getUser(), config.getPassword());
            list = executeQuery(con, "show variables like 'secure_file_priv'");
            if (list != null && list.size() == 1)
                path = (String) list.get(0).get("Value");
        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
            JdbcUtils.close(con);
        }
        return path;
    }

    public static void main(String[] args) {
        String result = "\n" + "--\n" + "-- Position to start replication or point-in-time recovery from\n" + "--\n"
                + "\n" + "CHANGE MASTER TO MASTER_LOG_FILE='NANGE-PC-bin.000021', MASTER_LOG_POS=154;\n";
        int logIndex = result.indexOf("MASTER_LOG_FILE='");
        int logPosIndex = result.indexOf("MASTER_LOG_POS=");
        String logFile = result.substring(logIndex + 17, logIndex + 17 + result.substring(logIndex + 17).indexOf("'"));
        String logPos = result.substring(logPosIndex + 15, logPosIndex + 15 + result.substring(logPosIndex + 15).indexOf(";"));
        System.out.println(logFile + logPos);
    }
}

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