Group replication message cache size not configurable
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
MySQL InnoDB Cluster Charm |
Fix Committed
|
Wishlist
|
Mert Kirpici |
Bug Description
The system variable group_replicati
Syslog showing recurring OOM kills for mysqld every ~ 12 hours
ubuntu@
-- Logs begin at Mon 2022-05-30 14:23:41 UTC, end at Fri 2022-06-03 10:26:22 UTC. --
May 31 13:51:27 juju-bae646-
Jun 01 13:02:50 juju-bae646-
Jun 02 12:46:40 juju-bae646-
Here is the result of a query taken from MySQL docs[2] that shows the aggragated memory usage for different subsystems, from a node with 2G system memory:
mysql> SELECT SUBSTRING_
-> code_area, FORMAT_
-> AS current_alloc
-> FROM sys.x$memory_
-> GROUP BY SUBSTRING_
-> ORDER BY SUM(current_alloc) DESC;
+------
| code_area | current_alloc |
+------
| memory/innodb | 644.31 MiB |
| memory/group_rpl | 454.70 MiB |
| memory/
| memory/sql | 55.81 MiB |
| memory/mysys | 33.96 MiB |
| memory/temptable | 12.00 MiB |
| memory/
| memory/mysqlx | 3.25 KiB |
| memory/myisam | 728 bytes |
| memory/csv | 120 bytes |
| memory/blackhole | 120 bytes |
| memory/vio | 80 bytes |
+------
Current value:
mysql> select @@group_
+------
| @@group_
+------
| 1024.00000000 |
+------
Current implementation defaults a similar variable, innodb_
I suggest that also needs to be exposed through the charm configuration.
---
[1] https:/
[2] https:/
Changed in charm-mysql-innodb-cluster: | |
assignee: | nobody → Mert Kırpıcı (mertkirpici) |
As long as we don't break anyone on charm upgrade I think this make sense. I propose that the new charm config is unset by default. The charm can then check what it is set to and if it's unset continue with the current behaviour of defaulting to 1Gb.