compression database height

Error message

compression database height({compression_db_height}) is less than target height({target_block_height})

What it means

The compression database variant of the height guard in rollback_to: its height is Optional (None is fine), but a recorded height below target_block_height aborts the rollback because the compression DB cannot be advanced by a rollback. This keeps compressed-state history consistent with the chain height being rolled back to.

Solutions

Run the node until the compression DB records heights up to the chain height, then retry the rollback.
Pick a target_block_height no greater than the compression DB height if that history must be kept.
If compression history is rebuildable, clear the compression database and let it re-initialize (height None is permitted).

Defensive patterns

Strategy: validation

Validate before calling

if let Some(comp_height) = combined_db.compression().latest_height_from_metadata()? {
    if target_block_height > comp_height {
        anyhow::bail!("target {} above compression DB height {}", target_block_height, comp_height);
    }
}

Try / catch

match combined_db.rollback_to(target, &mut shutdown) {
    Ok(()) => Ok(()),
    Err(e) if e.to_string().contains("compression database height") => {
        // let compression writer catch up, or cap the target at its height
        let cap = combined_db.compression().latest_height_from_metadata()?.unwrap_or(target);
        combined_db.rollback_to(target.min(cap), &mut shutdown)
    }
    Err(e) => Err(e),
}

Prevention

Don't toggle the compression feature on an existing chain mid-height without re-baselining its DB.
Watch compression writer errors: silent failures leave its height stale.
Compression height is Optional — prefer wiping and rebuilding over rolling back a lagging DB.

When it happens

Trigger: rollback_to with target_block_height above the compression database's recorded height — compression registry/state stopped being written before the target, or the compression DB was restored from an older snapshot than the rest.

Common situations: Compression feature enabled mid-chain or disabled for a period; partial snapshot restore omitting newer compression data; compression writer failures going unnoticed while the chain advanced.

Related errors

AI-assisted analysis of FuelLabs/fuel-core@b9d4d170da (2026-08-16). Data as JSON: /api/errors/978aadf510e37df7. Report an issue: GitHub.

Appendix: source

Thrown at crates/fuel-core/src/combined_database.rs:549

                return Err(anyhow::anyhow!(
                    "off-chain database height({off_chain_height}) \
                    is less than target height({target_block_height})"
                ));
            }

            if let Some(gas_price_chain_height) = gas_price_chain_height
                && gas_price_chain_height < target_block_height
            {
                return Err(anyhow::anyhow!(
                    "gas-price database height({gas_price_chain_height}) \
                    is less than target height({target_block_height})"
                ));
            }

            if let Some(compression_db_height) = compression_db_height
                && compression_db_height < target_block_height
            {
                return Err(anyhow::anyhow!(
                    "compression database height({compression_db_height}) \
                    is less than target height({target_block_height})"
                ));
            }

            if on_chain_height > target_block_height {
                self.on_chain().rollback_last_block()?;
            }

            if off_chain_height > target_block_height {
                self.off_chain().rollback_last_block()?;
            }

            if let Some(gas_price_chain_height) = gas_price_chain_height
                && gas_price_chain_height > target_block_height
            {
                self.gas_price().rollback_last_block()?;
            }

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