[HIVE-10474] LLAP: investigate why TPCH Q1 1k is slow

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Component/s: llap
• Assignee: Unassigned
• Reporter: Sergey Shelukhin
• Created: 23/Apr/15 23:16
• Updated: 17/Dec/15 09:40
• Resolved: 20/May/15 23:08

Description

While most queries run faster in LLAP than just Tez with container reuse, TPCH Q1 is much slower.
On my run, on tez with container reuse (current default LLAP configuration but mode == container and no daemons running) runs 2-6 (out of 6 consecutive runs in the same session) finished in 25.5sec average; with 16 LLAP daemons in default config the average was 35.5sec; same w/o IO elevator (to rule out its impact) it took 59.7sec w/strange distribution (later runs were slower than earlier runs, still, fastest run was 49.5sec).

So excluding IO elevator it's more than 2x degradation.

We need to figure out why this is happening. Is it just slot discrepancy? Regardless, this needs to be addressed.

Issue Links

• duplicates: HIVE-10772 LLAP: perf dips with IO elevator disabled