risingwavelabs/risingwave · error · SinkError

Nats error: {0}

Error message

Nats error: {0}

What it means

SinkError::Nats(anyhow::Error) in src/connector/src/sink/mod.rs:1143 wraps failures from the NATS sink connector, keeping the source anyhow::Error and backtrace from the NATS client. Raised when establishing a connection to the NATS server, authenticating, or publishing to a subject fails.

Source

Thrown at src/connector/src/sink/mod.rs:1142

        anyhow::Error,
    ),
    #[error("ClickHouse error: {0}")]
    ClickHouse(String),
    #[error("Redis error: {0}")]
    Redis(String),
    #[error("Http error: {0}")]
    Http(
        #[source]
        #[backtrace]
        anyhow::Error,
    ),
    #[error("Mqtt error: {0}")]
    Mqtt(
        #[source]
        #[backtrace]
        anyhow::Error,
    ),
    #[error("Nats error: {0}")]
    Nats(
        #[source]
        #[backtrace]
        anyhow::Error,
    ),
    #[error("Google Pub/Sub error: {0}")]
    GooglePubSub(
        #[source]
        #[backtrace]
        anyhow::Error,
    ),
    #[error("Doris/Starrocks connect error: {0}")]
    DorisStarrocksConnect(
        #[source]
        #[backtrace]
        anyhow::Error,
    ),
    #[error("Doris error: {0}")]

View on GitHub (pinned to 6469eb736d)

Solutions

1. Verify connectivity with nats --server <url> pub test hi (and matching creds) and correct the server URL/credentials in the sink options.
2. Check auth configuration: token, user/password, or .creds file path and freshness.
3. Compare message size against the server's max_payload (INFO) and reduce the encoded payload if it exceeds the limit.
4. Fix the URL scheme (nats:// vs tls://) and provide CA material if TLS is required.
5. Inspect the wrapped NATS client error in RisingWave logs to pinpoint connect vs publish stage.

Example fix

// before: publish exceeds server max_payload
CREATE SINK nats_sink FROM mv WITH (
  connector = 'nats', server_url = 'nats://nats:4222', subject = 'rw.events'
);
// after: reduce encoded row size or raise server max_payload
CREATE SINK nats_sink FROM mv WITH (
  connector = 'nats', server_url = 'nats://nats:4222', subject = 'rw.events',
  format = 'append only', encode = 'json'
);

# Verify NATS server, auth, and payload limits before creating the sink
nats --server "$NATS_URL" --creds creds.creds pub rw.health check
nats --server "$NATS_URL" server info | grep -i max_payload

fn is_valid_nats_url(url: &str) -> bool {
    url.starts_with("nats://") || url.starts_with("tls://")
}

// Reconnect on transient errors; fail fast on authz errors
match sink_result {
    Err(SinkError::Nats(e)) if is_transient(&e) => retry_with_backoff(),
    Err(SinkError::Nats(e)) if is_authz(&e) => fix_credentials_and_restart_sink(),
    Err(e) => alert(&e.to_string()),
    Ok(v) => process(v),
}

When it happens

Trigger: CREATE SINK ... WITH (connector='nats') when: the server URL is wrong or unreachable, authentication/authorization fails (credentials file, token, or user/pass), TLS handshake fails, or a publish fails (max payload exceeded, no responders for request-reply, connection closed).

Common situations: nats:// vs tls:// scheme mismatch; expired or rotated NATS credentials (nsc operator account); server max_payload smaller than the encoded sink message; NATS server restarted and sink did not reconnect cleanly.

Related errors

• Redis error: {0}
• Http error: {0}
• Mqtt error: {0}
• SinkError::Nats(anyhow!(e))
• failed to parse response body

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/2684166c7e6a7567. Report an issue: GitHub.