[MDEV-33206] MariaDB Read Utilization is very high Created: 2024-01-09  Updated: 2024-01-12

Status: Needs Feedback
Project: MariaDB Server
Component/s: Server
Affects Version/s: 10.11.5
Fix Version/s: None

Type: Bug Priority: Major
Reporter: ASHWANI SINGH Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: MariaDB-server
Environment:

Linux

Attachments: PNG File image-2024-01-10-01-49-27-565.png     PNG File image-2024-01-10-01-50-07-138.png    

 Description   

Hi Team,

We have found that on our MariaDB Version 10.11.5 read requests are very high as per iostat & iotop command but in mysql processlist.

I can't see any queries coming to it and even no-one is executing any queries to it.
The Server on which we are facing this issue is a read replica of another MariaDB Server.

Both server version is identical.
And on Master DB i can see read & write is under control even though that DB is serving the live requests.
While on Read Replica we are observing high read requests from MariaDb
Please find attached screenshot.

 Comments   
Comment by Daniel Black [ 2024-01-10 ]

Can you use bcc-tools and look at filetop to see which files are being read?

Comment by ASHWANI SINGH [ 2024-01-10 ]

Hi Daniel,

Do we have any guide or documentation on how to use it.
If any package needs to be installed what are those packages please share guide.

Comment by Daniel Black [ 2024-01-10 ]

> If any package needs to be installed what are those packages please share guide.

bcc-tools. Varies slightly per distro, usually a similar name.

> Do we have any guide or documentation on how to use it.

Per link. filetop (could be named bcc-filetop), Could restrict to mariadb process with -p {pid}, and maybe a 5 or more second summary is easier to process. If its lots of small temporary files maybe less is better, depends what shows up.

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