apache/shardingsphere · error · InvalidParameterValueException

invalid value for parameter "client_encoding": "%s"

Error message

invalid value for parameter "client_encoding": "%s"

What it means

Error "invalid value for parameter "client_encoding": "%s"" thrown in apache/shardingsphere.

Source

Thrown at proxy/frontend/dialect/postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/authentication/PostgreSQLAuthenticationEngine.java:156

        PostgreSQLComStartupPacket startupPacket = new PostgreSQLComStartupPacket(payload);
        clientEncoding = getNormalizedClientEncoding(startupPacket.getClientEncoding());
        context.channel().attr(CommonConstants.CHARSET_ATTRIBUTE_KEY).set(StandardCharsets.UTF_8);
        String username = startupPacket.getUsername();
        ShardingSpherePreconditions.checkNotEmpty(username, EmptyUsernameException::new);
        startupMessageReceived = true;
        context.writeAndFlush(getIdentifierPacket(username, rule));
        currentAuthResult = AuthenticationResultBuilder.continued(username, "", startupPacket.getDatabase(), startupPacket.getConnectionAttributes());
        return currentAuthResult;
    }
    
    private String getNormalizedClientEncoding(final String clientEncoding) {
        String formattedClientEncoding = formatClientEncoding(clientEncoding);
        String lowerCaseClientEncoding = formattedClientEncoding.toLowerCase(Locale.ROOT);
        boolean isDefault = "default".equals(lowerCaseClientEncoding);
        boolean isUtf8 = "utf8".equals(lowerCaseClientEncoding) || "utf-8".equals(lowerCaseClientEncoding) || "utf_8".equals(lowerCaseClientEncoding)
                || "unicode".equals(lowerCaseClientEncoding);
        if (!isDefault && !isUtf8) {
            throw new InvalidParameterValueException("client_encoding", lowerCaseClientEncoding);
        }
        return PostgreSQLCharacterSets.UTF8.name();
    }
    
    private String formatClientEncoding(final String value) {
        return value.startsWith("'") && value.endsWith("'") || value.startsWith("\"") && value.endsWith("\"") ? value.substring(1, value.length() - 1).trim() : value.trim();
    }
    
    private PostgreSQLIdentifierPacket getIdentifierPacket(final String username, final AuthorityRule rule) {
        Optional<Authenticator> authenticator = rule.findUser(new Grantee(username)).map(optional -> new AuthenticatorFactory<>(PostgreSQLAuthenticatorType.class, rule).newInstance(optional));
        if (authenticator.isPresent() && PostgreSQLAuthenticationMethod.PASSWORD.getMethodName().equals(authenticator.get().getAuthenticationMethodName())) {
            return new PostgreSQLPasswordAuthenticationPacket();
        }
        md5Salt = PostgreSQLRandomGenerator.getInstance().generateRandomBytes(4);
        return new PostgreSQLMD5PasswordAuthenticationPacket(md5Salt);
    }
}

View on GitHub (pinned to e952770a21)

Solutions

1. Set client_encoding to a valid PostgreSQL encoding name such as UTF8.
2. Remove the invalid client_encoding setting from the connection startup packet.
3. Check for typos in the encoding name.

When it happens

Trigger: The client supplies an unrecognized client_encoding value in the PostgreSQL startup/authentication phase.

Common situations: Misspelled or unsupported charset names (e.g. 'utf-8' vs 'UTF8') in connection parameters.

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/67304ca701f24d76. Report an issue: GitHub.