Limitation

This feature is not supported for virtual warehouses that use workload-aware autoscaling

When an Impala virtual warehouse has been auto-suspended, you can submit as many queries as desired. All these queries will be queued with the message:

Query queued. Latest queuing reason: Waiting for executors to start.
Only DDL queries and queries scheduled only on the coordinator
(either NUM_NODES set to 1 or when small query optimization is
triggered) can currently run.

Once the virtual warehouse resumes, all queued queries will be admitted and executed simultaneously. The limit defined in the llama.am.throttling.maximum.queued.reservations setting in llama-site.xml still applies. These limitations are due to a known issue tracked at IMPALA-13965. There is currently no workaround for these issues.

Query counts are synchronized across the cluster by using the statestore. Because the statestore uses an eventually consistent model, the system may admit more queries than the configured limit when multiple queries start at the same time.