What causes "Hummock error: {0}" in risingwavelabs/risingwave?

Inspect the wrapped inner Hummock error for the concrete cause (IO, credentials, timeout).

risingwavelabs/risingwave · error · MetaError

Hummock error

Error message

Hummock error: {0}

What it means

MetaError::HummockError wraps the Hummock (RisingWave's cloud-native storage engine) error type into the meta error enum, displayed as 'Hummock error: {inner}'. Any failure in the state-store layer touched from the meta service (SST operations, version management, remote storage) surfaces through this wrapper.

Solutions

Inspect the wrapped inner Hummock error for the concrete cause (IO, credentials, timeout).
Verify object-store configuration (endpoint, bucket, credentials) and connectivity from the meta/worker nodes.
Retry transient failures; for persistent GC/version errors, check hummock state in the meta catalog.
Consult storage logs on both meta and compute nodes to localize which component failed.

Defensive patterns

Strategy: retry

Validate before calling

// Verify object-store reachability before Hummock-heavy operations
let ok = s3_client.head_bucket(BucketName).await.is_ok();
assert!(ok, "object store must be reachable before meta operations");

Type guard

fn is_hummock_error(e: &MetaError) -> bool {
    matches!(e, MetaError::HummockError(_))
}

Try / catch

match commit_hummock_version().await {
    Err(e @ MetaError::HummockError(inner)) if is_transient(&inner) => {
        retry_with_backoff(3, || commit_hummock_version()).await?
    }
    other => other?,
}

Prevention

Validate object-store credentials/bucket config at startup with a smoke test.
Set up monitoring on S3/object-store error rates and latency.
Distinguish transient (network/timeout) from permanent (config) inner errors before retrying.

When it happens

Trigger: Meta-side Hummock operations failing via #[from] HummockError — e.g. committing new Hummock versions, GC/compaction scheduling, or reading object metadata — typically due to S3/object-store issues or version conflicts.

Common situations: Misconfigured or unreachable object storage (wrong S3 credentials/bucket); network problems to the object store; Hummock version conflicts after node restarts; full or throttled storage backends.

Related errors

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/ede15c39be26bf3c. Report an issue: GitHub.

Appendix: source

Thrown at src/meta/src/error.rs:52

    thiserror::Error,
    thiserror_ext::ReportDebug,
    thiserror_ext::Arc,
    thiserror_ext::Construct,
    thiserror_ext::Macro,
)]
#[thiserror_ext(
    newtype(name = MetaError, backtrace, extra_provide = Self::provide_postgres_error_code),
    macro(path = "crate::error")
)]
pub enum MetaErrorInner {
    #[error("Metadata model error: {0}")]
    MetadataModelError(
        #[from]
        #[backtrace]
        MetadataModelError,
    ),

    #[error("Hummock error: {0}")]
    HummockError(
        #[from]
        #[backtrace]
        HummockError,
    ),

    #[error(transparent)]
    RpcError(
        #[from]
        #[backtrace]
        RpcError,
    ),

    #[error("{0}")]
    PermissionDenied(String),

    #[error("Invalid worker: {0}, {1}")]
    InvalidWorker(WorkerId, String),

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