Re: [Lse-tech] [OSDL] dbt1 Scaling

[Jenny Z. <je...@os...>]

I will check with SAPDB engineers regarding those questions.

It turned out that the database shutdown because the disk is full.
I did one run on 2.5.29(with no patch) and SAPDB 7.3.0.25.
The results are available at 
http://www.osdl.org/projects/dbt1prfrns/results/
under linux-2.5.29-2x400. I am using raw devices for my database so it
is not affected by IDE driver as the 1tier results.

Comparing to the same run on 2.4.18 kernel(under
linux-2.4.18-2x400-kernprof), I observed slower database response time
in the file 'BT', but the difference is not very big. Other than that,
the data collected on both kernels are very close. 

I will do more runs on the same kernel with different users to see if
the scalability curve is the same. Then I will do some tests as you
suggested later this week.

Jenny

On Fri, 2002-08-09 at 19:18, Gerrit Huizenga wrote:
> In message <200...@wo...>, > : Andi Kleen writes:
> > On Fri, Aug 09, 2002 at 05:30:47PM -0700, Gerrit Huizenga wrote:
> > >
> > > Also, do you know if sapdb uses AIO (asynchronous IO) on any platforms?
> > > Would it benefit from AIO on Linux?
> > 
> > There is some posix AIO support in the source code for other Unixes. 
> > Last time I looked it wasn't used on linux though, it uses threaded IO instead.
> > It could be enabled by fixing some ifdefs and recompiling.
> > 
> > Another useful change would be probably to change it to use O_DIRECT. Then
> > it could work with files instead of raw partitions and it would be also
> > possible to measure differences between rawio and O_DIRECT. I checked
> > with the sapdb developers some time ago and they told me that all the 
> > IO buffers should be already sufficiently aligned for O_DIRECT, so 
> > changing it should be very simple.
> 
> This is great to know.  We are doing a lot of work like this with
> DB2 but it would be nice if someone could repeat some of our
> work externally, especially when using purely open source tools.
> We can also use that to compare the results to what we are seeing
> internally to provide comparisons between the stress points on
> the kernel between the various applications.
> 
> gerrit
-- 
Jenny Zhang
Open Source Development Lab Inc 
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Beaverton, OR 97006
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