CacheStore cannot be used on the worker node! healthcheck wa

Error message

CacheStore cannot be used on the worker node! healthcheck was used.

What it means

CacheStore::healthcheck on worker nodes is an unconditional panic! stub (cache_rocksstore.rs:2092), so even a health probe routed to the worker cache store crashes with this message. It exists purely as a guard: these CacheStore operations must never be called in worker mode.

Source

Thrown at rust/cubestore/cubestore/src/cachestore/cache_rocksstore.rs:2092

    async fn compaction(&self) -> Result<(), CubeError> {
        panic!("CacheStore cannot be used on the worker node! compaction was used.")
    }

    async fn info(&self) -> Result<CachestoreInfo, CubeError> {
        panic!("CacheStore cannot be used on the worker node! info was used.")
    }

    async fn eviction(&self) -> Result<EvictionResult, CubeError> {
        panic!("CacheStore cannot be used on the worker node! eviction was used.")
    }

    async fn persist(&self) -> Result<(), CubeError> {
        panic!("CacheStore cannot be used on the worker node! persist was used.")
    }

    async fn healthcheck(&self) -> Result<(), CubeError> {
        panic!("CacheStore cannot be used on the worker node! healthcheck was used.")
    }

    async fn rocksdb_properties(&self) -> Result<Vec<RocksPropertyRow>, CubeError> {
        panic!("CacheStore cannot be used on the worker node! rocksdb_properties was used.")
    }

    async fn wipe(&self) -> Result<(), CubeError> {
        panic!("CacheStore cannot be used on the worker node! wipe was used.")
    }
}

crate::di_service!(ClusterCacheStoreClient, [CacheStore]);

#[cfg(test)]
mod tests {
    use super::*;
    use crate::cachestore::{CacheEvictionPolicy, EvictionFinishedResult};
    use crate::config::{init_test_logger, ConfigObjImpl, CubeServices};

View on GitHub (pinned to 7d981676b3)

Solutions

Point health checks at the master node's store/endpoint
Use a worker-appropriate health probe instead of CacheStore::healthcheck
Complete role detection before installing health-check loops

Example fix

// before
// probe on all nodes
store.healthcheck().await?;
// after
if is_master { store.healthcheck().await?; } else { worker_healthcheck().await?; }

Defensive patterns

Strategy: fallback

Validate before calling

if is_master { store.healthcheck().await?; } else { worker_probe().await?; }

Type guard

fn health_probe_available(store: &dyn CacheStore) -> bool { node_role == NodeRole::Master }

Try / catch

let ok = std::panic::catch_unwind(AssertUnwindSafe(|| store.healthcheck())).map(|r| r.is_ok()).unwrap_or(false);

Prevention

Use worker-appropriate health endpoints for workers
Never probe CacheStore::healthcheck on non-master nodes
Configure load balancers with role-specific health paths
Complete role detection before health loops start

When it happens

Trigger: Calling CacheStore::healthcheck() on a worker-node CacheStore (cache_rocksstore.rs:2092), typically from a health-check loop or load-balancer probe wired to the wrong endpoint.

Common situations: Load balancers/health probes targeting worker nodes with a master-only health endpoint; startup code that probes the store before role detection completes.

Related errors

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/c4056cc6a6f1b312. Report an issue: GitHub.