Thursday, September 1, 2016

Hive LLAP (Live Long and Process)

hive> set hive.llap.execution.mode=none;

to change into llap mode use the following command

hive> set hive.llap.execution.mode=all;

LLAP is an optional daemon process running on multiple nodes, that provides the following

- Caching and data reuse across queries with compressed columnar data in-memory

- Multi threaded execution including reads with predicate pushdown and hash join

- High throughput IO using Asynch IO Elevator with dedicated thread and core per disk

- Granular column level security across applications