risingwavelabs/risingwave · error · HummockError

CompactionGroup error: {0}

Error message

CompactionGroup error: {0}

What it means

HummockError::CompactionGroupError (src/storage/src/hummock/error.rs:71-72, constructor compaction_group_error at error.rs:165-167) wraps failures from the compaction-group subsystem, which manages which SSTables belong to which compaction/group configuration (e.g. groups registered with the meta service, ACL/worker-group filtering). It is thrown when group metadata lookup, registration, or update fails or is inconsistent.

Source

Thrown at src/storage/src/hummock/error.rs:71

    #[error("Time-travel version expired: table {table_id}, epoch {epoch}")]
    TimeTravelVersionExpired { table_id: TableId, epoch: u64 },
    #[error(
        "Committed epoch mismatch: table {table_id}, committed_epoch {committed_epoch}, read_epoch {read_epoch}"
    )]
    CommittedEpochMismatch {
        table_id: TableId,
        committed_epoch: u64,
        read_epoch: u64,
    },
    #[error("Barrier read is unavailable for now. Likely the cluster is recovering")]
    ReadCurrentEpoch,
    #[error("CompactionExecutor error: {0}")]
    CompactionExecutor(String),
    #[error("FileCache error: {0}")]
    FileCache(String),
    #[error("SstObjectIdTracker error: {0}")]
    SstObjectIdTrackerError(String),
    #[error("CompactionGroup error: {0}")]
    CompactionGroupError(String),
    #[error("SstableUpload error: {0}")]
    SstableUploadError(String),
    #[error("Read backup error: {0}")]
    ReadBackupError(String),
    #[error("Foyer error: {0}")]
    FoyerError(#[from] foyer::Error),
    #[error("Other error: {0}")]
    Other(String),
}

impl HummockError {
    pub fn invalid_format_version(v: u32) -> HummockError {
        HummockErrorInner::InvalidFormatVersion(v).into()
    }

    pub fn invalid_block() -> HummockError {
        HummockErrorInner::InvalidBlock.into()

View on GitHub (pinned to 6469eb736d)

Solutions

1. Verify the compaction group referenced in the error still exists in meta (query meta's compaction-group tables or metrics)
2. Re-trigger compaction or the table/group registration; transient meta desync often resolves on the next scheduling pass
3. Ensure cleanup/drop operations completed fully; if a group was manually deleted, restore it or recreate affected tables/materialized views
4. Upgrade all nodes to the same version if the error appeared after a rolling upgrade

Example fix

// before: compactor panics on missing group state
// after: validate group existence before scheduling
let groups = hummock_manager.list_compaction_groups().await?;
let group_exists = groups.iter().any(|g| g.id == task.compaction_group_id);
if !group_exists {
    // skip/reschedule instead of surfacing CompactionGroup error
    return Ok(CompactionStatus::Ignored);
}

// before scheduling compaction for a task, confirm the group exists
let groups = hummock_manager.list_compaction_groups().await?;
assert!(
    groups.iter().any(|g| g.id == task.compaction_group_id),
    "compaction group {} no longer exists",
    task.compaction_group_id
);

fn is_compaction_group_err(e: &HummockError) -> bool {
    e.to_report_string().starts_with("CompactionGroup error:")
}

match schedule_compaction(task).await {
    Err(e) if is_compaction_group_err(&e) => {
        warn!(error = %e.report(), group = task.compaction_group_id, "group state invalid; rescheduling");
        CompactionStatus::Ignored // let scheduler re-derive group state
    }
    other => other,
}

When it happens

Trigger: Looking up or updating a compaction group's config (member tables, compaction config) via the meta client fails; a table is mapped to a group that no longer exists; validating compaction-group state during compactor task scheduling.

Common situations: Objects belonging to a group deleted while a compaction task referencing them is still in flight; manual table/group manipulation or cleanup tools desynchronizing meta state; version upgrade changing group metadata schema.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• SST {0} is invalid
• Failed to get compaction task for compaction_group {}
• Unsupported task type for copy-on-write iceberg compaction:
• CompactionExecutor error: {0}
• SstObjectIdTracker error: {0}

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/9252af6f478f45a1. Report an issue: GitHub.