VM live metrics in XenServer with Xen Orchestra

Apr 8, 2015

Because this is really important, we'll release this feature next week! As a result, this post is also about announcing Xen Orchestra 3.9.

Let's see it immediately in action:

Why performance metrics matter

The goal of live performance metrics are various. But in a Virtual Machine case, it's pretty clear:

  • you can see any problem/spike in less than 1 second
  • it's easy to read
  • it's live, so you can track a specific problem without waiting
  • it helps to debug/benchmark your infrastructure (what's limiting my application performance?)

And because XenServer is really cool, it gives us a lot of data. The challenge is to get AND display them.

Remember: metrics are not like supervision, not the same goals. But it's also a fantastic tool.

Thus, this time, imagine this scenario:

  • you are using XOA Enterprise, so you can delegate VMs to your developer team
  • they can only see their VM in Xen Orchestra, and thus their metrics
  • they can start their software, and see the impact on the VMs performances (disks, network, CPU, RAM)

Great isn't it?

Metrics in XenServer

How to fetch VM metrics/data in XenServer was already covered in this previous article: Statistics in XO. But in a few words, those metrics are stored on RRD-like files written in XML, on each the host where the VM is currently running.

Here is how it works:

  • the file is downloaded by xo-server
  • the XML is parsed
  • finally, numbers are sent to the client, in this case: xo-web.

XenServer uses multiple sample rate: last 10 minutes, the sample rate is 5 seconds. You got also last 2 hours, last week and last year, with respectively 1 minute, 1 hour and 1 day of sample rate.

In Xen Orchestra

Since last year, we planned to integrate those metrics. Our initial draft was:

And the "real" result is:

Let's zoom:

When you click on a chart, you got it on the whole panel:

This feature is also great when you make benchmarks. In this video, we'll start a disk benchmark on Windows 7 on XenServer 6.5. You'll see instantly the Disk I/O chart rocketing to the sky!

XO 3.9!

Yes, this will be the last stop before 4.0! And this 3.9 should be out Friday, the 17th. Hang on!

Olivier Lambert

Vates CEO & co-founder, Xen Orchestra and XCP-ng project creator. Enthusiast entrepreneur and Open Source advocate. A very happy Finnish Lapphund owner.