Node blacklisting in Impala

Learn how Impala Coordinators use node blacklisting to quickly identify and mitigate unhealthy or unavailable executors, minimizing query failures in dynamic cluster environments.

Node Blacklisting allows Impala Coordinators to be more aggressive about deciding that an executor is unhealthy or unavailable, to minimize failed queries in environments where cluster membership maybe more variable, rather than having to wait on the statestore heartbeat mechanism to decide that the executor is down.

Node blacklists are local to a coordinator. A node is put on the blacklist based on information from failed queries. Nodes are only blacklisted temporarily, and are taken off the blacklist after a certain period of time.