FETCH_ROWS_TIMEOUT_MS Query Option

Use the FETCH_ROWS_TIMEOUT_MS query option to control how long Impala waits for query results when clients fetch rows.

When this query option is set to 0, fetch requests wait indefinitely.

The timeout applies both when query result spooling is enabled and disabled:

When result spooling is disabled (SPOOL_QUERY_RESULTS = FALSE), the timeout controls how long a client waits for a single row batch to be produced by the coordinator.
When result spooling is enabled ( (SPOOL_QUERY_RESULTS = TRUE), a client can fetch multiple row batches at a time, so this timeout controls the total time a client waits for row batches to be produced.

The timeout also applies to fetch requests issued against queries in the 'RUNNING' state. A 'RUNNING' query has no rows available, so any fetch request will wait until the query transitions to the 'FINISHED' state and for it to fetch all requested rows. A query in the 'FINISHED' state means that the rows are available to be fetched.

Type: INT

Default: 10000 (10 seconds)

Added in: Impala 3.4