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| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
| <concept id="node_blacklisting"> |
| <title>Impala Node Blacklisting</title> |
| <conbody> |
| <p>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.</p> |
| <p>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.</p> |
| </conbody> |
| </concept> |
