CacheStore cannot be used on the worker node! truncate was u

Error message

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

What it means

ClusterCacheStoreClient (worker-node CacheStore) panics on truncate for the same reason as other methods: truncating the cache is master-only and workers must not touch local cache storage. It is a fail-fast guard against state divergence in the cluster.

Source

Thrown at rust/cubestore/cubestore/src/cachestore/cache_rocksstore.rs:1961

impl CacheStore for ClusterCacheStoreClient {
    async fn cache_all(&self, _limit: Option<usize>) -> Result<Vec<IdRow<CacheItem>>, CubeError> {
        panic!("CacheStore cannot be used on the worker node! cache_all was used.")
    }

    async fn cache_set(
        &self,
        _item: CacheItem,
        _update_if_not_exists: bool,
    ) -> Result<bool, CubeError> {
        panic!("CacheStore cannot be used on the worker node! cache_set was used.")
    }

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

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

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

    async fn cache_get(&self, _key: String) -> Result<Option<IdRow<CacheItem>>, CubeError> {
        panic!("CacheStore cannot be used on the worker node! cache_get was used.")
    }

    async fn cache_keys(&self, _prefix: String) -> Result<Vec<IdRow<CacheItem>>, CubeError> {
        panic!("CacheStore cannot be used on the worker node! cache_keys was used.")
    }

    async fn cache_incr(&self, _: String) -> Result<IdRow<CacheItem>, CubeError> {
        panic!("CacheStore cannot be used on the worker node! cache_incr was used.")
    }

View on GitHub (pinned to 7d981676b3)

Solutions

Run truncate on the master node only, which owns and coordinates cache storage.
Exclude worker nodes from maintenance scripts that call CacheStore mutation methods.
Reconfigure the node as master if it is intended to hold the cache.

Example fix

// before
worker_cache_store.truncate().await?; // panics on worker
// after
master_cache_store.truncate().await?; // run maintenance on master

Defensive patterns

Strategy: validation

Validate before calling

if node_role() == Role::Worker {
    return Err(CubeError::internal("truncate is master-only"));
}
cache_store.truncate().await?;

Type guard

fn is_master_cache(store: &dyn CacheStore) -> bool {
    std::any::Any::type_id(store) != std::any::TypeId::of::<ClusterCacheStoreClient>()
}

Try / catch

if is_worker_cache_stub(cache_store) {
    return Err(CubeError::internal("truncate must run on the master node"));
}
cache_store.truncate().await?;

Prevention

Run truncation maintenance exclusively on the master
Exclude workers from destructive maintenance loops
Verify deployment topology before wiping cache storage
Gate truncate behind role checks in shared utilities

When it happens

Trigger: Calling truncate() on a worker node's ClusterCacheStoreClient, e.g. maintenance jobs wiping cache tables on every node.

Common situations: Maintenance/CI scripts running truncate against all cluster nodes; misrouting maintenance traffic to workers.

Related errors

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/14c95b0a05b1850c. Report an issue: GitHub.