CERN Data Centre Evolution
Gavin McCance
gavin.mccance@cern.ch
@gmccance
SDCD12: Supporting Science with Cloud Computing
Bern
19th November 2012
What is CERN ?
• Conseil Européen pour la
Recherche Nucléaire – aka
European Laboratory for
Particle Physics
• Between Geneva and the
Jura mountains, straddling
the Swiss-French border
• Founded in 1954 with an
international treaty
• Our business is fundamental
physics , what is the
universe made of and how
does it work
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Answering fundamental questions…
• How to explain particles have mass?
We have theories and accumulating experimental evidence.. Getting close…
• What is 96% of the universe made of ?
We can only see 4% of its estimated mass!
• Why isn’t there anti-matter
in the universe?
Nature should be symmetric…
• What was the state of matter just
after the « Big Bang » ?
Travelling back to the earliest instants of
the universe would help…
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The Large Hadron Collider (LHC) tunnel
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•
Data Centre by Numbers
– Hardware installation & retirement
•
~7,000 hardware movements/year; ~1,800 disk failures/year
Racks
828
Disks
64,109
Tape Drives
160
Servers
11,728
Raw disk capacity (TiB)
63,289
Tape Cartridges
45,000
Processors
15,694
Memory modules
56,014
Tape slots
56,000
Cores
64,238
Memory capacity (TiB)
Tape Capacity (TiB)
73,000
HEPSpec06
Xeon
3GHz
4%
Xeon
L5520
33%
482,507
Xeon Xeon
5150 5160
2% 10%
158
RAID controllers
3,749
High Speed Routers
(640 Mbps → 2.4 Tbps)
Other Fujitsu
0%
3%
Xeon
E5335
7%
Xeon
E5345
14%
Ethernet Switches
Hitachi
23%
Seagate
15%
10 Gbps ports
HP
0%
Switching Capacity
Maxtor
0%
Xeon
L5420
8%
Xeon
E5410
16%
Xeon
E5405
6%
Western
Digital
59%
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1 Gbps ports
10 Gbps ports
24
350
2,000
4.8 Tbps
16,939
558
IT Power Consumption
2,456 KW
Total Power Consumption
3,890 KW
6
Current infrastructure
• Around 12k servers
–
–
–
–
Dedicated compute, dedicated disk server, dedicated service nodes
Majority Scientific Linux (RHEL5/6 clone)
Mostly running on real hardware
Last couple of years, we’ve consolidated some of the service nodes
onto Microsoft HyperV
– Various other virtualisation projects around
• In 2002 we developed our own management toolset
– Quattor / CDB configuration tool
– Lemon computer monitoring
– Open source, but a small community
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• Many diverse applications (”clusters”)
• Managed by different teams (CERN IT + experiment groups)
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New data centre to expand capacity
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• Data centre in Geneva
at the limit of
electrical capacity at
3.5MW
• New centre chosen in
Budapest, Hungary
• Additional 2.7MW of
usable power
• Hands off facility
• Deploying from 2013
with 200Gbit/s
network to CERN
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Time to change strategy
• Rationale
– Need to manage twice the servers as today
– No increase in staff numbers
– Tools becoming increasingly brittle and will not scale as-is
• Approach
– CERN is no longer a special case for compute
– Adopt an open source tool chain model
– Our engineers rapidly iterate
• Evaluate solutions in the problem domain
• Identify functional gaps and challenge old assumptions
• Select first choice but be prepared to change in future
– Contribute new function back to the community
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Building Blocks
mcollective, yum
Bamboo
Puppet
AIMS/PXE
Foreman
JIRA
OpenStack
Nova
git
Koji, Mock
Yum repo
Pulp
Active Directory /
LDAP
Lemon /
Hadoop
Hardware
database
Puppet-DB
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Choose Puppet for Configuration
• The tool space has exploded in last few years
– In configuration management and operations
• Puppet and Chef are the clear leaders for ‘core tools’
• Many large enterprises now use Puppet
–
–
–
–
Its declarative approach fits what we’re used to at CERN
Large installations: friendly, wide-based community
You can buy books on it
You can employ people who know it better than do
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Puppet Experience
• Excellent: basic puppet is easy to setup
and can be scaled-up well
• Well documented, configuring services with it is easy
• Handle our cluster diversity and dynamic clouds well
• Lots of resource (“modules”) online, though of varying quality
• Large, responsive community to help
• Lots of nice tooling for free
– Configuration version control and branching: integrates well with git
– Dashboard: we use the Foreman dashboard
• We’re moving all our production service over in 2013
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Preparing the move to cloud
• Improve operational efficiency and dynamicness
– Dynamic multiple operating system demand
– Dynamic temporary load spikes for special activities
– Hardware interventions with long running programs (live migration)
• Improve resource efficiency
– Exploit idle resources, especially waiting for disk and tape I/O
– Highly variable load such as interactive or build machines
• Enable cloud architectures
– Gradual migration from traditional batch + disk to cloud interfaces and
workflows
• Improve responsiveness
– Self-Service with coffee break response time
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What is OpenStack ?
• OpenStack is a cloud operating system that controls large
pools of compute, storage, and networking resources
throughout a datacenter, all managed through a dashboard
that gives administrators control while empowering their users
to provision resources through a web interface
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Service Model
• Pets are given names like
pussinboots.cern.ch
• They are unique, lovingly hand raised
and cared for
• When they get ill, you nurse them back
to health
• Cattle are given numbers like
vm0042.cern.ch
• They are almost identical to other cattle
• When they get ill, you get another one
• Future application architectures should use Cattle but Pets with
strong configuration management are viable and still needed
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Basic Openstack Components
HORIZON
KEYSTONE
GLANCE
NOVA
Compute
Registry
Scheduler
Image
Volume
Network
• Each component has an API and is pluggable
• Other non-core projects interact with these components
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Supporting the Pets with OpenStack
• Network
– Interfacing with legacy site DNS and IP management
– Ensuring Kerberos identity before VM start
• Puppet
– Ease use of configuration management tools with our users
– Exploit mcollective for orchestration/delegation
• External Block Storage
– Currently using nova-volume with Gluster backing store
• Live migration to maximise availability
– KVM live migration using Gluster
– KVM and Hyper-V block migration
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Current Status of OpenStack at CERN
• Working on an Essex code base from the EPEL repository
– Excellent experience with the Fedora cloud-sig team
– Cloud-init for contextualisation, oz for images with RHEL/Fedora
• Components
– Current focus is on Nova with KVM and Hyper-V
– Keystone running with Active Directory and Glance for Linux and
Windows images
• Pre-production facility with around 200 Hypervisors, with
2000 VMs integrated with CERN infrastructure
– used for simulation of magnet placement using LHC@Home and batch
physics programs
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Next Steps
• Deploy into production at the start of 2013 with Folsom running
production services and compute on top of OpenStack IaaS
• Support multi-site operations with 2nd data centre in Hungary
• Exploit new functionality
– Ceilometer for metering
– Bare metal for non-virtualised use cases such as high I/O servers
– X.509 user certificate authentication
– Load balancing as a service
Ramping to 15K hypervisors with 100K
VMs by 2015
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Conclusions
• CERN computer centre is expanding
• We’re in the process of refurbishing the tools we use
to manage the centre based on Openstack for IaaS
and Puppet for configuration management
• Production at CERN in next few months on Folsom
– Gradual migration of all our services
• Community is key to shared success
– CERN contributes and benefits
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BACKUP SLIDES
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Training and Support
•
•
•
•
Buy the book rather than guru mentoring
Follow the mailing lists to learn
Newcomers are rapidly productive (and often know more than us)
Community and Enterprise support means we’re not on our own
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Staff Motivation
• Skills valuable outside of CERN when an engineer’s contracts
end
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When communities combine…
• OpenStack’s many components and options make
configuration complex out of the box
• Puppet forge module from PuppetLabs does our configuration
• The Foreman adds OpenStack provisioning for user kiosk to a
configured machine in 15 minutes
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Foreman to manage Puppetized VM
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Active Directory Integration
• CERN’s Active Directory
–
–
–
–
Unified identity management across the site
44,000 users
29,000 groups
200 arrivals/departures per month
• Full integration with Active Directory via LDAP
– Uses the OpenLDAP backend with some particular configuration
settings
– Aim for minimal changes to Active Directory
– 7 patches submitted around hard coded values and additional filtering
• Now in use in our pre-production instance
– Map project roles (admins, members) to groups
– Documentation in the OpenStack wiki
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What are we missing (or haven’t found yet) ?
• Best practice for
– Monitoring and KPIs as part of core functionality
– Guest disaster recovery
– Migration between versions of OpenStack
• Roles within multi-user projects
– VM owner allowed to manage their own resources (start/stop/delete)
– Project admins allowed to manage all resources
– Other members should not have high rights over other members VMs
• Global quota management for non-elastic private cloud
– Manage resource prioritisation and allocation centrally
– Capacity management / utilisation for planning
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Opportunistic Clouds in online experiment farms
• The CERN experiments have farms of 1000s of Linux servers
close to the detectors to filter the 1PByte/s down to 6GByte/s
to be recorded to tape
• When the accelerator is not running, these machines are
currently idle
– Accelerator has regular maintenance slots of several days
– Long Shutdown due from March 2013-November 2014
• One of the experiments are deploying OpenStack on their farm
– Simulation (low I/O, high CPU)
– Analysis (high I/O, high CPU, high network)
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New architecture data flows
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