CERN Data Centre Evolution

CERN Data Centre Evolution

Gavin [email protected]

@gmccance

SDCD12: Supporting Science with Cloud ComputingBern

19th November 2012

mailto:[email protected]

What is CERN ?

Gavin McCance, CERN 2

• 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


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-matterin the universe?

Nature should be symmetric…

• What was the state of matter justafter the « Big Bang » ?

Travelling back to the earliest instants ofthe universe would help…

4

The Large Hadron Collider (LHC) tunnel

Gavin McCance, CERN


• Data Centre by Numbers– Hardware installation & retirement

• ~7,000 hardware movements/year; ~1,800 disk failures/year

Xeon 51502%

Xeon 516010%

Xeon E5335

7%Xeon

E534514%

Xeon E5405

6%

Xeon E541016%

Xeon L5420

8%

Xeon L552033%

Xeon 3GHz4%

Fujitsu3%

Hitachi23% HP

0% Maxtor

0% Seagate15%

Western Digital

59%

Other0%

High Speed Routers(640 Mbps → 2.4 Tbps) 24

Ethernet Switches 350

10 Gbps ports 2,000

Switching Capacity 4.8 Tbps

1 Gbps ports 16,939

10 Gbps ports 558

Racks 828

Servers 11,728

Processors 15,694

Cores 64,238

HEPSpec06 482,507

Disks 64,109

Raw disk capacity (TiB) 63,289

Memory modules 56,014

Memory capacity (TiB) 158

RAID controllers 3,749

Tape Drives 160

Tape Cartridges 45,000

Tape slots 56,000

Tape Capacity (TiB) 73,000

IT Power Consumption 2,456 KW

Total Power Consumption 3,890 KW

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


• Many diverse applications (”clusters”) • Managed by different teams (CERN IT + experiment groups)


New data centre to expand capacity


• 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

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


Building Blocks


Bamboo

Koji, Mock

AIMS/PXEForeman

Yum repoPulp

Puppet-DB

mcollective, yum

JIRA

Lemon /Hadoop

git

OpenStack Nova

Hardware database

Puppet

Active Directory /LDAP

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


Puppet Experience

• Excellent: basic puppet is easy to setupand 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


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


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


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

Basic Openstack Components


Compute Scheduler

NetworkVolume

Registry Image

KEYSTONE HORIZON

NOVA

GLANCE

• Each component has an API and is pluggable• Other non-core projects interact with these components

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


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


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


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


BACKUP SLIDES


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


Staff Motivation

• Skills valuable outside of CERN when an engineer’s contracts end


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


http://forge.puppetlabs.com/

Foreman to manage Puppetized VM


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


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


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)


New architecture data flows


CERN Data Centre Evolution

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