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Posted to issues@hive.apache.org by "Oleksiy Sayankin (Jira)" <ji...@apache.org> on 2020/02/19 09:25:00 UTC
[jira] [Work started] (HIVE-22911) Locks entries are left over
inside HIVE_LOCKS when using DbTxnManager
[ https://issues.apache.org/jira/browse/HIVE-22911?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Work on HIVE-22911 started by Oleksiy Sayankin.
-----------------------------------------------
> Locks entries are left over inside HIVE_LOCKS when using DbTxnManager
> ---------------------------------------------------------------------
>
> Key: HIVE-22911
> URL: https://issues.apache.org/jira/browse/HIVE-22911
> Project: Hive
> Issue Type: Bug
> Reporter: Oleksiy Sayankin
> Assignee: Oleksiy Sayankin
> Priority: Critical
>
> We found lots of orphan/old/leftover lock entries inside {{HIVE_LOCKS}}. There are more than 120k locks in HIVE_LOCKS of MySQL database. We also checked the top 3 tables which are related to the existing locks:
>
> {code}
> mysql> select HL_DB,HL_TABLE, count(*) from HIVE_LOCKS group by 1,2 order by 3 desc limit 10;
> +-----------+------------------------------+----------+
> | HL_DB | HL_TABLE | count(*) |
> +-----------+------------------------------+----------+
> | db1 | table1 | 66984 |
> | db1 | table2 | 33208 |
> | db1 | table3 | 9315 |
> …
> {code}
> For table “db1. table1”, here are 3 Hive sessions related, and each of the Hive session is waiting for 22328 read locks. This is because this table “db1. table1” is a huge partition table, and it has more than 200k child partitions. I am guessing each of Hive session was trying to do a full table scan on it. I group-by based on column {{HL_LAST_HEARTBEAT}} instead, here is the list:
>
> {code}
> MariaDB [customer]> select cast(FROM_UNIXTIME(HL_LAST_HEARTBEAT/1000) as date) as dt,count(*) as cnt from HIVE_LOCKS
> -> group by 1 order by 1;
> +------------+--------+
> | dt | cnt |
> +------------+--------+
> | 1969-12-31 | 2 |
> | 2019-05-20 | 10 |
> | 2019-05-21 | 3 |
> | 2019-05-23 | 5 |
> | 2019-05-24 | 2 |
> | 2019-05-25 | 1 |
> | 2019-05-29 | 7 |
> | 2019-05-30 | 2 |
> | 2019-06-11 | 13 |
> | 2019-06-28 | 3 |
> | 2019-07-02 | 2 |
> | 2019-07-04 | 5 |
> | 2019-07-09 | 1 |
> | 2019-07-15 | 2 |
> | 2019-07-16 | 1 |
> | 2019-07-18 | 2 |
> | 2019-07-20 | 3 |
> | 2019-07-29 | 5 |
> | 2019-07-30 | 9 |
> | 2019-07-31 | 7 |
> | 2019-08-02 | 2 |
> | 2019-08-06 | 5 |
> | 2019-08-07 | 17 |
> | 2019-08-08 | 8 |
> | 2019-08-09 | 5 |
> | 2019-08-21 | 1 |
> | 2019-08-22 | 20 |
> | 2019-08-23 | 1 |
> | 2019-08-26 | 5 |
> | 2019-08-27 | 98 |
> | 2019-08-28 | 3 |
> | 2019-08-29 | 1 |
> | 2019-09-02 | 3 |
> | 2019-09-04 | 3 |
> | 2019-09-05 | 105 |
> | 2019-09-06 | 3 |
> | 2019-09-07 | 2 |
> | 2019-09-09 | 6 |
> | 2019-09-12 | 9 |
> | 2019-09-13 | 1 |
> | 2019-09-17 | 1 |
> | 2019-09-24 | 3 |
> | 2019-09-26 | 6 |
> | 2019-09-27 | 4 |
> | 2019-09-30 | 1 |
> | 2019-10-01 | 2 |
> | 2019-10-03 | 9 |
> | 2019-10-04 | 2 |
> | 2019-10-06 | 1 |
> | 2019-10-08 | 1 |
> | 2019-10-09 | 1 |
> | 2019-10-10 | 6 |
> | 2019-10-11 | 1 |
> | 2019-10-16 | 13 |
> | 2019-10-17 | 1 |
> | 2019-10-18 | 2 |
> | 2019-10-19 | 2 |
> | 2019-10-21 | 10 |
> | 2019-10-22 | 6 |
> | 2019-10-28 | 2 |
> | 2019-10-29 | 4 |
> | 2019-10-30 | 2 |
> | 2019-10-31 | 2 |
> | 2019-11-05 | 2 |
> | 2019-11-06 | 2 |
> | 2019-11-11 | 1 |
> | 2019-11-13 | 1 |
> | 2019-11-14 | 1 |
> | 2019-11-21 | 4 |
> | 2019-11-26 | 1 |
> | 2019-11-27 | 1 |
> | 2019-12-05 | 4 |
> | 2019-12-06 | 2 |
> | 2019-12-12 | 1 |
> | 2019-12-14 | 1 |
> | 2019-12-15 | 3 |
> | 2019-12-16 | 1 |
> | 2019-12-17 | 1 |
> | 2019-12-18 | 1 |
> | 2019-12-19 | 2 |
> | 2019-12-20 | 2 |
> | 2019-12-23 | 1 |
> | 2019-12-27 | 1 |
> | 2020-01-07 | 1 |
> | 2020-01-08 | 14 |
> | 2020-01-09 | 2 |
> | 2020-01-12 | 372 |
> | 2020-01-14 | 2 |
> | 2020-01-15 | 1 |
> | 2020-01-20 | 11 |
> | 2020-01-21 | 119253 |
> | 2020-01-23 | 113 |
> | 2020-01-24 | 4 |
> | 2020-01-25 | 536 |
> | 2020-01-26 | 2132 |
> | 2020-01-27 | 396 |
> | 2020-01-28 | 1 |
> | 2020-01-29 | 3 |
> | 2020-01-30 | 11 |
> | 2020-01-31 | 11 |
> | 2020-02-03 | 2 |
> | 2020-02-04 | 4 |
> | 2020-02-05 | 5 |
> | 2020-02-06 | 8 |
> | 2020-02-10 | 32 |
> | 2020-02-11 | 15 |
> | 2020-02-12 | 14 |
> | 2020-02-13 | 1 |
> | 2020-02-14 | 92 |
> +------------+--------+
> 109 rows in set (0.16 sec)
> {code}
>
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