risingwavelabs/risingwave · error · TimeTravel

prev_version {} not found

Error message

prev_version {} not found

What it means

During time-travel metadata truncation, each previous-version ID planned for deletion is looked up in the hummock_time_travel_version table inside the transaction. If find_by_id returns no row, the code returns Error::TimeTravel("prev_version {} not found") — a lookup failure indicating the version row is missing while the deletion plan still references it.

Source

Thrown at src/meta/src/hummock/manager/time_travel.rs:343

                if sst_ids_to_delete.len() >= delete_sst_batch_size {
                    delete_sst_in_batch(
                        &txn,
                        std::mem::take(&mut sst_ids_to_delete),
                        delete_sst_batch_size,
                    )
                    .await?;
                }
                let new_object_ids = delta_to_delete.newly_added_object_ids();
                object_ids_to_delete.extend(&new_object_ids - &retained_snapshot_object_ids);
            }
        }
        for prev_version_id in version_ids_to_delete {
            let prev_version = {
                let prev_version = hummock_time_travel_version::Entity::find_by_id(prev_version_id)
                    .one(&txn)
                    .await?
                    .ok_or_else(|| {
                        Error::TimeTravel(anyhow!(format!(
                            "prev_version {} not found",
                            prev_version_id
                        )))
                    })?;
                IncompleteHummockVersion::from_persisted_protobuf_owned(
                    prev_version.version.to_protobuf(),
                )
            };
            let sst_ids = prev_version.get_sst_ids();
            sst_ids_to_delete.extend(&sst_ids - &retained_snapshot_sst_ids);
            if sst_ids_to_delete.len() >= delete_sst_batch_size {
                delete_sst_in_batch(
                    &txn,
                    std::mem::take(&mut sst_ids_to_delete),
                    delete_sst_batch_size,
                )
                .await?;
            }

View on GitHub (pinned to 6469eb736d)

Solutions

1. Check the hummock_time_travel_version table for the reported version id to confirm it is genuinely missing.
2. Prevent concurrent time-travel GC from running in parallel; run a single GC coordinator.
3. Restore meta store consistency from a backup or rebuild time-travel metadata if rows are missing.
4. File a bug with logs and the version id — a missing row here usually signals an internal consistency bug.

// verify prev-version rows exist before planning deletion
let existing: HashSet<_> = version_ids_to_delete.iter()
    .filter(|id| version_exists_in_store(id))
    .cloned().collect();
let dangling: Vec<_> = version_ids_to_delete.difference(&existing).collect();
if !dangling.is_empty() { /* abort: inconsistent metadata */ }

// catch the typed error and treat as consistency alarm
match meta.delete_time_travel_metadata(...).await {
    Err(Error::TimeTravel(e)) if e.to_string().contains("prev_version") => {
        // halt GC, snapshot meta store state for diagnosis
    }
    other => other,
}

When it happens

Trigger: Calling delete_time_travel_metadata when a hummock_time_travel_version row for prev_version_id was already removed (concurrent truncation, manual DB cleanup) or the pinning/version snapshot lists versions that no longer exist in the store.

Common situations: Racing version GC workers; manual deletes against the meta store database; corrupted or partially restored meta store after a crash or restore operation.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

• version delta {} not found
• too many inflight time travel queries, max_inflight_time_tra
• time-travel version expired: table {table_id}, epoch {epoch}
• time travel
• object {object_id} is rejected from being committed since it

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/ebfe8492671c7c58. Report an issue: GitHub.