Bug 376448

Summary: mysql poor performance
Product: [openSUSE] openSUSE 10.3 Reporter: Samuel Kroslak <samopal>
Component: KernelAssignee: Nick Piggin <npiggin>
Status: RESOLVED NORESPONSE QA Contact: E-mail List <qa-bugs>
Severity: Major    
Priority: P5 - None CC: jeffm, jnelson-suse
Version: Final   
Target Milestone: ---   
Hardware: i586   
OS: openSUSE 10.3   
Whiteboard:
Found By: Customer Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---
Attachments: sql-bench

Description Samuel Kroslak 2008-04-02 18:04:06 UTC
Created attachment 205787 [details]
sql-bench

I want to continue with bug id=335584 which was marked as resolved because no answer. I can see very similar behavior on my OpenSUSE 10.3 box with default mysql  5.0.45 that can be found in repository. I also have regular installation of OpenSUSE with no special kernel or kernel customizations. I tried to run ./run-all-tests --server=mysql --log --user=root --password=*** command from mysql-bench package and I attached results. I'm not very keen in DB stuff, but I certainly know that the databases I'm running on my box are X-times slower than in Windows or other linux OS on same HW configuration.
Comment 1 Nick Piggin 2008-05-23 01:59:07 UTC
Thanks for keeping at it.

A couple of things spring to mind. Firstly, I believe SUSE kernels try to do the right thing WRT disk writeback caching, wheras some other distros and I think even the upstream kernel doesn't do by default. Also, we default to data=ordered on journalling filesystems.

Could you try ext3 mounted with -o barrier=0 data=writeback ?

The other thing is that we've had a few scalability problems in the Linux kernel in general with a funny interaction between the kernel, mysql, and glibc's malloc/free. Although this only seems to cause a problem on very CPU bound workloads and servers with about 8 or more cores.
Comment 2 Nick Piggin 2008-07-31 03:19:14 UTC
Any updates on this issue?
Comment 3 Samuel Kroslak 2008-07-31 06:09:22 UTC
sorry guys, but I no longer use OpenSUSE, so I can't help right now, maybe I'll return to it in 1-2 months and then I can try to play with it and see what I can find out 
Comment 4 Nick Piggin 2008-09-10 10:26:29 UTC
Well I'll close this bug now. Thanks anyway for reporting, and sorry I couldn't help this time.