Riza Suminto 4236c307b9 IMPALA-10465: Use IGNORE variant of Kudu write operations ...

KUDU-1563 added support for INSERT_IGNORE, UPDATE_IGNORE, and
DELETE_IGNORE to handle cases where users want to ignore primary key
errors efficiently. Impala already does this today for its INSERT
behavior. However, it does so by ignoring the per-row errors from Kudu
client side. This requires a large error buffer (which may need to be
expanded in rare cases) to log all of the warning messages which users
often do not care about and causes significant RPC overhead.

This patch change the Kudu write operation by Impala to use
INSERT_IGNORE, UPDATE_IGNORE, and DELETE_IGNORE if Kudu cluster supports
it and backend flag "kudu_ignore_conflicts" is true.

We benchmark the change by doing insert and update query on modified
tpch.lineitem table where we introduce conflicts for around half of the
total rows being modified. The table below shows the performance
difference after the patch:

+----------------------+--------+-------------+------------+------------+----------------+
| Query                | Avg(s) | Base Avg(s) | Delta(Avg) | StdDev(%)  | Base StdDev(%) |
+----------------------+--------+-------------+------------+------------+----------------+
| KUDU-IGNORE-3-UPDATE | 30.06  | 30.52       |   -1.53%   |   0.18%    |   0.58%        |
| KUDU-IGNORE-2-INSERT | 48.91  | 71.09       | I -31.20%  |   0.60%    |   0.72%        |
+----------------------+--------+-------------+------------+------------+----------------+

Testing:
- Pass core tests.

Change-Id: I8da7c41d61b0888378b390b8b643238433eb3b52
Reviewed-on: http://gerrit.cloudera.org:8080/18536
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>

2022-05-26 08:47:24 +00:00

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