risingwavelabs/risingwave · error · SinkError

`{STREAM}` and `{STREAM_COLUMN}` only one can be set

Error message

`{STREAM}` and `{STREAM_COLUMN}` only one can be set

What it means

For `redis_value_type = 'stream'` sinks with a primary key, the Redis stream target must be given via exactly one of the mutually exclusive options `stream` (static stream key) or `stream_column` (a column holding the stream key). Setting both, or neither, fails the sink build with this SinkError::Config.

Source

Thrown at src/connector/src/sink/formatter/mod.rs:395

                None => {
                    let template = b.format_desc.options.get(VALUE_FORMAT).ok_or_else(|| {
                        SinkError::Config(anyhow!("Cannot find '{VALUE_FORMAT}',please set it."))
                    })?;
                    Ok(TemplateEncoder::new_string(
                        b.schema,
                        pk_indices,
                        template.clone(),
                    ))
                }
            },
            REDIS_VALUE_TYPE_STREAM => match pk_indices {
                Some(_) => {
                    let stream = b.format_desc.options.get(STREAM).cloned();
                    let stream_column = b.format_desc.options.get(STREAM_COLUMN).cloned();
                    if (stream.is_none() && stream_column.is_none())
                        || (stream.is_some() && stream_column.is_some())
                    {
                        return Err(SinkError::Config(anyhow!(
                            "`{STREAM}` and `{STREAM_COLUMN}` only one can be set"
                        )));
                    }
                    TemplateEncoder::new_pubsub_stream_key(
                        b.schema,
                        pk_indices,
                        stream,
                        stream_column,
                    )
                }
                None => {
                    let value_template =
                        b.format_desc.options.get(VALUE_FORMAT).ok_or_else(|| {
                            SinkError::Config(anyhow!(
                                "Cannot find '{VALUE_FORMAT}',please set it."
                            ))
                        })?;
                    let key_template = b.format_desc.options.get(KEY_FORMAT).ok_or_else(|| {

View on GitHub (pinned to 6469eb736d)

Solutions

  1. Keep exactly one of `stream = 'my-stream'` or `stream_column = 'stream_col'`; remove the other.
  2. Use `stream_column` for per-row dynamic stream keys, `stream` for a single fixed stream.
  3. Re-create the sink after cleaning the WITH options.

Example fix

// before
WITH (redis_value_type='stream', stream='events', stream_column='topic');
// after
WITH (redis_value_type='stream', stream_column='topic');  -- or stream='events' only
Defensive patterns

Strategy: validation

Validate before calling

if value_type == "stream" {
    let s = with_options.contains_key("stream");
    let sc = with_options.contains_key("stream_column");
    if s == sc {
        return Err("Set exactly one of `stream` or `stream_column`".into());
    }
}

Try / catch

match result {
    Err(e) if e.to_string().contains("only one can be set") => {
        eprintln!("Fix stream options (keep exactly one of stream/stream_column): {}", e);
    }
    other => other?,
}

Prevention

When it happens

Trigger: Creating a Redis stream sink with a primary key where the WITH options include both `stream` and `stream_column`, or neither of them.

Common situations: Users migrate from a pubsub sink and leave a `channel`-like mix of options behind, or they copy both a static stream name and a stream column from an example and keep both.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/7c4f09bde84e34c5. Report an issue: GitHub.