[MCOL-5489] Query Cache Overload Causing PrimProc OOM Created: 2023-05-01  Updated: 2023-06-09  Resolved: 2023-06-09

Status: Closed
Project: MariaDB ColumnStore
Component/s: None
Affects Version/s: None
Fix Version/s: 23.02.4

Type: Bug Priority: Blocker
Reporter: Todd Stoffel (Inactive) Assignee: Roman
Resolution: Fixed Votes: 0
Labels: None

Issue Links:
PartOf
is part of MCOL-5499 Same host communication has an unlimi... Closed
Problem/Incident
is caused by MCOL-5499 Same host communication has an unlimi... Closed
is caused by MCOL-5500 cgroups v2 support with version autod... Closed

 Description   

In cases where the size of a ColumnStore table exceed the amount of RAM on the server, the following two scenarios cause PrimProc to run up the RAM consumption on the system until the process is whacked by the OOM killer.

SELECT * INTO OUTFILE '/tmp/result.txt'
 
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
 
LINES TERMINATED BY '\n'
 
FROM columnstore_table;


INSERT INTO innodb_table SELECT * FROM columnstore_table;



 Comments   
Comment by Daniel Lee (Inactive) [ 2023-06-09 ]

Builds verified:

develop:
engine: ab9b95e3683250ca88960147994474b049ef6395
server: 770caf2440e71f035ca2beded85e1cb398a704aa
buildNo: 7964

develop-23.02
engine: 42c7df4a347441a6326eaa14700cb615a4061eb8
server: 770caf2440e71f035ca2beded85e1cb398a704aa
buildNo: 7968

Repeated the test case in both develop and develop-23.02 branches. Succeeded.

MariaDB [mytest]> SELECT * INTO OUTFILE '/tmp/result.txt'
 
    -> FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
 
    -> LINES TERMINATED BY '\n'
 
    -> FROM lineitem;
 
Query OK, 119972104 rows affected (4 min 8.722 sec)

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