In this talk, we will give an overview of the state of the Xen Project, trends that impact the project, see whether challenges that surfaced last year have been addressed and how we did it, and highlight new challenges and solutions for the coming year.

1. Lars Kurth
Community Manager, Xen Project
Chairman, Xen Project Advisory Board
lars_kurth

3. Diamond Sponsor Silver Sponsor

5. Xen & KVM Hackathon
Tue 14:00 – 18:00
Virginia Room, 4th floor, Union Street Tower
Joint Xen & KVM Social Event
Tue 18:30 – 21:00
Shuttle Bus Stop: Union St side @ Sheraton
Garage Billiards
1130 Broadway Seattle, WA 98122
(15 min walk, maps are available at registration)

6. Discussion Groups
Lead to take notes (or nominate someone to do so)
and post to xen-devel@
Free slots:
Come to me or use stickers

7. Lunch is not provided
Lots of venues nearby
Maps are available at the event registration desk
Developer Meeting
Wed 10:00 – 13:30
Lunch provided
Seneca, 4th floor, Union Street Tower
Sign up via wiki.xenproject.org/wiki/Developer_Meeting/Aug2015
Or come and see me

9. Subprojects (retired, new, established)
Project Initiatives
Statistics

11. 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Hypervisor Developer list traffic : Q3 2003 - now
Hypervisor team / subproject : hypervisor and tools
XAPI toolstack (used in XenServer)
PVOPS (Xen enabled Linux) Linux Kernel Dev.
XenServer.orgXCP
BSD’s, Grub, QEMU, FreeRTOS, …
Xen on ARM PV Xen on ARM non-PV
Embedded & Auto
Windows PV
Mirage OS
Libvirt, CentOS, …
AGL, Android, …

12. 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Hypervisor Developer list traffic : Q3 2003 - now
Hypervisor team / subproject : hypervisor and tools
XAPI toolstack (used in XenServer)
PVOPS (Xen enabled Linux) Linux Kernel Dev.
Xen on ARM non-PV
Embedded & Auto
Windows PV
Mirage OS
PVOPS & Xen on
ARM are complete
(achieved their goals)
In incubation
Mirage OS fulfills criteria for graduation
(no formal review has been conducted)
Xen on ARM PV

14. 1 Rack at EarthLink in Marlborough, MA
More than 4 times test capacity
Testing against Linux, BSDs & up/downstreams
24 test machines, planning to expand with another rack
Automated performance testing
Early stages
We do have a lot more test contributions
Xen Project Rack
0
300
600
900
1200
2003 - 2012 2013 2014 2015

16. (Goal: group A alongside KVM)

17. the people/companies who drove this
Xen Project Test Lab
Lead: Ian Jackson
Top Test Contributors: Ian Campbell, Wei Liu, Dario Faggioli, Roger Pau
Monne, Longtao Pang, Anthony Perard
Xen Project – OpenStack CI Loop
Lead: Bob Ball
Team:
Anthony Perard, Antony Messerli, Jim Fehlig, Stefano Stabellini, Konrad Wilk
Special Thanks:
Rackspace for donating significant hosting capacity to get this project started

18. 0
50
100
150
200
250
2010 2011 2012 2013 2014 2015*
Developers
Employers
0
2000
4000
6000
8000
10000
12000
14000
2010 2011 2012 2013 2014 2015
CommitsContributors
*) Up to Aug 11th

19. 24%
23%
51%
2%
Hypervisor
XAPI
Mirage OS
Win PV Drivers

20. Contribution Statistics
(Up to Aug 11th, 2015)
Diversity
Project Operations

21. 0
500
1000
1500
2000
2500
3000
2011 2012 2013 2014 2015
Projection
Commits
Fairly stable
over the last
few years.

22. (contributions > 1%)
88%
1% 11%
Citrix
Suse
Linaro
Oracle
Intel
Verizon
Fujitsu
Cavium
Analog Devices
AMD
Zentific
NSA
Xilinx
Novetta
BitDefender
Other

23. 49%
18%
8%
4%
3%
2%
1%
1%
1%
1% 12%
Citrix
Suse
Linaro
Oracle
Intel
Verizon
Fujitsu
Cavium
Analog Devices
AMD
Zentific
NSA
Xilinx
Novetta
BitDefender
Other
(contributions > 1%, 2015 to Aug 11th)
2014
64%
13%
4%
4%
5%
2% 1%
4%
2015

25. 0
5
10
15
20
25
30
35
40
2010 2011 2012 2013 2014 2015 2016
4.0 4.1 4.2 4.3 4.4 4.5
Xen 4.x Number of New Major Features
4.6

26. Releases Process
From Soft to Hard Freeze – created some stress and pain
Security Process
Allow Service Providers to Upgrade During embargo
Pre-disclosure list application
Mechanism for pre-disclosure members to collaborate
Contributor Training
New influx of developers from China (access to Xen Project resources)
Gave training in Shanghai, Nanjing and Hangzhou
Focus on Designs for complex features
Worked generally very well
Some issues around sign-off by all stake-holders and ensuring
designs are up-to-date

27. Formalizing Feature Maturity Lifecycle
Proposal at lists.xenproject.org/archives/html/xen-devel/2015-06/msg01992.html
Important, because “supported features” have to be handled by security@

28. Started seeing issues Last Year
How are we doing Today?
What Next?
(Stats up to Aug 11th, 2015)

29. 0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
40.00%
45.00%
50.00%
Up to 1 week 1 to 2 weeks 2 to 3 weeks 3 to 6 weeks 6 to 13 weeks 13 to 52 weeks More than 1
year
July 2013 - Jan 2014
Feb 2014 - Aug 2014
Jan 2015 - Jul 2015
In 2015,
committed 1-4 year
old patches

30. 0
10
20
30
40
50
60
2012 2013 2014 2015
<1% of reviews
1-5% of reviews
>5% of reviews

31. 0
5000
10000
15000
20000
25000
30000
35000
2004 - 2010 2011 2012 2013 2014 2015
Replies to Patches est.
Patches Posted est.
Replies to Patches
Patches Posted
This reflects
a huge growth
jump in 1 year
While the
number of reviewers
has remained fixed
Aug 11th
On average
2.1 replies per patch
per patch revision

33. 0
1
2
3
4
5
2012 2013 2014 2015
Qemu
Xen
Patches posted & re-posted
(without review comments)
divided by patches gone into xen.git

34. Increasing number of contributions
Not enough review capacity to support growth; we know that review capacity has remained stable
 Increasing back-log (aka ongoing reviews on xendevel@)
Increasing number of review cycles per patch/patch set
Note: we know that the average number of review comments per patch version is stable
More disagreements amongst maintainers, reviewers & contributors
Lower quality contributions, requiring more review cycles
More complex contributions, requiring more review cycles
Increasing standards required to get code up-streamed (aka quality)
 Should be able to see patterns in review data
A combination of all/some of the above

35. We have an issue, but we do not understand exactly where
The 4 weeks before the 4.6 code freeze was the most stressful freeze in years
The Advisory Board is funding development of analysis tools for our review process
Insufficient research on what is normal/optimal
If you are planning larger contributions
You may want to help out with code reviews elsewhere
If you are planning to consistently contribute over several years
You may want to work towards ”building” Xen maintainers
BUT: this is no short term fix
Buying time
We may be able to buy us time through process changes
Discussion: search for “[xen 4.6 retrospective]” on xen-devel@
BoF: Xen 4.6 Retrospective Surgery & Developer Meeting

36. Events, Social Media, Press Coverage
Security Vulnerability Coverage

39. Average monthly web visits
grew by 37%
Social Media following
grew by 92%

40. 0
200
400
600
800
1000
1200
1400
Q1 '13 Q2' 13 Q3' 13 Q4' 13 Q1 '14 Q2 '14 Q3 '14 Q4' 14 Q1' 15 Q2' 15

43. Security stories are “hot”
Xen is widely used, thus security stories “sell”
It’s too easy for reporters to write a story
Reporters just have to check our page,
and know when the next story comes

44. Pro-active coverage of Xen stories (besides releases)

45. We discuss PR on publicity@lists.xenproject.org
(for our blog and elsewhere)
Sign up via lists.xenproject.org
Open to all community members
Avoid accidental creation of a
damaging news story

46. New Members
Please welcome Alibaba / Aliyun
Changes in Focus
From Operational/Reactive to Strategic
Community Support

48. Images used in this presentation are from
– Lars Kurth
– Xen Project and other Screen Shots
– 123RF.com & Shutterstock.com
– Peter Dedina @ flickr (page 17)
– Wajahat Mahmood @ flickr (page 33)