We have a observed a high memory usage by one of our MySQL(Oracle) instances running 5.6. We have verified the basic configurations and could find no clue about this. Below is the information that we captured during this analysis, please have a look at and let me hear back if you have anything to suggest.
- Data: Mostly Innodb
- Type of load: 95% SELECT
- Max connections: 100
- Max used connections: 10
- Current activity: Idle
- Uptime: 30 days
- Innodb buffer pool size: 5 GB(94% occupied by the time I post this)
- open table cache: 30000
- tables opened: 5
- DB total size: 14 GB(data & indexes)
NOTE: One thing that we have observed suspective is most of the space is occupied by 4 - 5 tables on the server and are all partitioned. When we check file descriptors in /proc/$pid/fd, we could see pointers to these partions. All these parttions are created with in last 30 days only. We are not sure why are these in memory and not released if they are in memory.
RAM being used is ~20 GB. Almost equalts to the size of innodb buffer + total size of the database. Please let us hearback in case if you need any other information.