risingwavelabs/risingwave · error · ConnectorError

Field ' ' is not allowed to be altered on the fly for…

Error message

Field '{field}' is not allowed to be altered on the fly for connection: {connection_name}

What it means

Generated-code guard for `ALTER CONNECTION`: the requested field is not in the CONNECTION_ALLOW_ALTER_ON_FLY_FIELDS whitelist for that connection type, so altering it on the fly fails. Generic whitelist check; the offending input is the field name not registered for the connection.

Solutions

  1. Alter only fields listed in the connection's allow_alter_on_fly registry.
  2. Drop and recreate the connection with the new field value if it is immutable.
  3. Correct field name spelling/case.
  4. Add the field to the allow list and regenerate if it should be mutable.

Example fix

// before
check_connection_allow_alter_on_fly_fields("privatelink", &["endpoint".into()])?;
// after
DROP CONNECTION privatelink;
CREATE CONNECTION privatelink WITH (... new endpoint ...);
Defensive patterns

Strategy: validation

Validate before calling

fn can_alter_connection(name: &str, field: &str) -> bool {
    connection_name_to_prop_type_name(name)
        .and_then(|t| CONNECTION_ALLOW_ALTER_ON_FLY_FIELDS.get(t))
        .map(|f| f.contains(&field.to_string()))
        .unwrap_or(false)
}

Try / catch

match check_connection_allow_alter_on_fly_fields(name, &fields) {
    Err(e) => suggest_recreate_connection(&e),
    Ok(()) => proceed(),
}

Prevention

When it happens

Trigger: Validating an ALTER on a connection field (e.g. a private-link field) that is not in CONNECTION_ALLOW_ALTER_ON_FLY_FIELDS for that connection type.

Common situations: Trying to mutate immutable connection fields (endpoint, port, credentials) without recreating the connection; field-name typo; attempting unsupported live schema change.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/a472da86e4432276. Report an issue: GitHub.

Appendix: source

Thrown at src/connector/src/with_options_test.rs:834

    connection_name: &str,
    fields: &[String],
) -> crate::error::ConnectorResult<()> {{
    use crate::source::connection_name_to_prop_type_name;

    // Convert connection name to the type name key
    let Some(type_name) = connection_name_to_prop_type_name(connection_name) else {{
        return Err(ConnectorError::from(anyhow::anyhow!(
            "Unknown connection: {{connection_name}}"
        )));
    }};
    let Some(allowed_fields) = CONNECTION_ALLOW_ALTER_ON_FLY_FIELDS.get(type_name) else {{
        return Err(ConnectorError::from(anyhow::anyhow!(
            "No allow_alter_on_fly fields registered for connection: {{connection_name}}"
        )));
    }};
    for field in fields {{
        if !allowed_fields.contains(field) {{
            return Err(ConnectorError::from(anyhow::anyhow!(
                "Field '{{field}}' is not allowed to be altered on the fly for connection: {{connection_name}}"
            )));
        }}
    }}
    Ok(())
}}

/// Checks if all given fields are allowed to be altered on the fly for the specified sink connector.
/// Returns Ok(()) if all fields are allowed, otherwise returns a `ConnectorError`.
pub fn check_sink_allow_alter_on_fly_fields(
    sink_name: &str,
    fields: &[String],
) -> crate::error::ConnectorResult<()> {{
    // TODO(#24846): JDBC sink currently uses `()` as sink config type in `for_all_sinks!`,
    // so it cannot have an isolated key in `SINK_ALLOW_ALTER_ON_FLY_FIELDS`.
    // Reuse the JDBC entry in `CONNECTION_ALLOW_ALTER_ON_FLY_FIELDS` for now.
    // TODO(#24846): remove this special case after JDBC sink has a dedicated config type
    // and allow-alter fields are generated directly into `SINK_ALLOW_ALTER_ON_FLY_FIELDS`.

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