WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] Xen Performance

The original question doesn't say "as measured on Dom0", and appears to reference the well known
study performed at Cambridge University and replicated at Clarkson University. That study used a handful
of benchmarks and compared throughput across a number of virtualization platforms. It found that, for those
tests, Xen throughput was, at most, only 8% worse than native Linux. 

The issue for our community, however, is that it is human nature to use the "at most 8% worse" 
as a data-point for Xen performance.  But throughput is not the whole picture. Many Xen installations 
are hosting user-facing web applications where response time is much more important than throughput.
Xen often increases the variability of response times.

One real world example:
native Linux:   page response times of (  400ms/150ms) [mean/standard deviation]
Xen VM: page response times of (  700ms/3.5s) [mean/standard deviation]

In this scenario, we have mean response times that are almost 100% worse, and the 90th percentile is 1000% worse.

Peter Booth

 


On May 28, 2009, at 1:08 PM, Javier Guerra wrote:

On Thu, May 28, 2009 at 11:57 AM, Peter Booth <peter_booth@xxxxxxx> wrote:

The 8% is a dangerous over-simplification, and represents simply the results
of a particular well-designed study.
 Clearly there are situations where the overhead of using Xen is much higher
than this.

but not as measured on Dom0, as i think the original question was

--
Javier

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users
<Prev in Thread] Current Thread [Next in Thread>