http://www.ngs.ac.uk
NGS Partnership: Why and How
Stephen Pickles
<stephen.pickles@manchester.ac.uk>
Technical Director, NGS
NGS Sustainability Workshop
Edinburgh, 22nd February, 2007
15th January, 2007
1
Partnership Programme
Goals:
1. Increase the range and depth of services and
resources that NGS can offer to its users
2. Provide leadership and guidance to sites needing to
put their resources “on the Grid”
15th January, 2007
2
Partners and Affiliates
Resource providers join NGS as Partners or Affiliates
• Partners provide significant resources or services to NGS users
– collect usage statistics (accounting)
– have formal Service Level Descriptions and production-quality support
arrangements
– have representation in NGS governance
• Affiliates retain total control over who has access to their resources
• Both
– require approval by NGS Board (meets quarterly)
• on basis of site’s SLD, “buddy’s” report, and Technical Board
recommendation
– are subject to continued monitoring and review
• partnership and affiliate status can be withdrawn by NGS Board
– exchange support and security contacts with NGS helpdesk
• users need a single point of contact for UK Grid
– in order to ensure that the NGS brand connotes reliable, production
services to users
15th January, 2007
3
NGS Compliance
Principle:
• If many NGS sites offer the same kind of service, they should use
compatible interfaces and protocols
• These are prescribed in the NGS Software Stack
– try to avoid mandating particular software versions, and verify
compliance through test suites
• Partners and affiliates are certified for compliance
– approval requires passing compliance test suite for seven days
– continuous monitoring and regular review
“One-off” and experimental services are tested, but not covered by
NGS Software Stack. All are vetted for:
• consistency with NGS security policies, and
• complementarity with NGS core services.
15th January, 2007
4
Partners with specialist
offerings
Westminster operates and supports P-GRADE portal and GEMLCA
services for NGS users, in addition to the usual Globus services
Belfast e-Science Centre (approved December 2006) provides:
• Basic Execution Services
– GridSAM instances configured for all NGS resources
• OMII-UK job submission software
• Service Hosting Service
– BeSC manage various web service containers into which projects or
VOs can deploy their own Web or Grid services
15th January, 2007
5
NGS & Partners, 2006
15th January, 2007
6
Membership pipeline
(not a complete list)
• Partners
– GridPP sites, initially Imperial, Glasgow
– Condor/Windows at Cardiff
• Affiliates
–
–
–
–
NW-Grid/Manchester SGI Prism
Microsoft HPC Cluster at Southampton
HECToR
SunGrid
• Data partners (early discussions)
– EDINA and MIMAS
• Others in discussion
15th January, 2007
7
Why join?
• Institutions have a mission to support their own
users
• Increasing dependence on computation & data,
and growing need to collaborate beyond the
institution, make “getting on the Grid” a
necessity for an institution to remain competitive
• NGS shows the way.
15th January, 2007
8
What’s in it for a partner?
• They get NO resources (people or hardware) from NGS (except
support)
• They have to expend effort to integrate their resources and support
arrangements into NGS
• They derive some value from NGS brand, expertise, support
networks, hand-holding,...
• They might hope to “trade” un-utilized cycles for other resources on
the “NGS market”, but this is not possible yet
• Joining should be approximately cost-neutral for an affiliate.
• But partners as asked to donate resources to the pool, and they
have no control over their disposition
– altruistic at the best of times,
– and now we have fEC!
Are we pinning the future of the NGS to hopes of an epidemic of
altruism?
15th January, 2007
9
Digression
Virtual Organisations and
Collaboration
15th January, 2007
10
Sharing and
Virtual Organisations
Share (v):
• To have part; to receive a portion; to partake, enjoy, or suffer with others.
R
R
?
R
R
R
R
R
VO C
R
?
VO A
R
R
?
R
R
R
“flexible, secure, coordinated resource
sharing among dynamic collections of
individuals, institutions, and resources"
15th January, 2007
R
VO B
?
R
R
R
"…enables communities (“virtual organizations”) to share
geographically distributed resources as they pursue
common goals -- assuming the absence of central location,
central control, omniscience, existing trust relationships."
11
Virtual Organisations
• Many different understandings of VO
• In the NGS view, there is
– a consumer-provider relationship between the VO and the Grid
– end users are members of (one or more) VOs
• VO notion has proved invaluable in making access management
scale
• VOs bring value to their members by:
–
–
–
–
sharing applications / tools / data
perhaps providing a community-oriented view of the Grid
negotiating community access rights with providers
...
15th January, 2007
12
Virtual Organisations
• NGS is moving steadily towards VO-based approaches
to:
– access management
• project-based requests for resources, accounting and authorisation
– resource requests from individual users will continue to be accepted
• resource providers decide what VOs to “support”
– and user engagement
• more effective to help communities with common needs than
individuals
• It’s still early days
– despite free use of VO terminology in Grid
• VOs are not yet first class entities in Grids
• there is little software to facilitate VO formation/management and
VO-based authorisation, and less that directly benefits end-users
15th January, 2007
13
What’s in it for a partner, again?
• Need to restore to partners some measure of control
over the disposition of resources in the NGS pool.
• Currently working towards a model in which:
–
–
–
–
NGS creates a VO (using VOMS) for each partner site
and associates with it a project allocation
the partner has full control over the membership of the VO
any member of the VO can access NGS partner resources
(affiliates could elect out of bands to support this VO)
– the allocation is either:
• primed in proportion to the donated resources, and/or
• topped up in proportion to usage of the partners’ resources made by
other sites
• Implied need for accounting, audit, “exchange rates”,...
15th January, 2007
14
Concluding remarks
• Partnership programme important for expansion of UK
Grid
– and integration of specialist resources and services (e.g.
datasets, visualization, instruments)
• NGS as integration fabric
– could evolve into unifying mechanism for UK compute provision?
• NGS as facilitator of collaboration
– joining the NGS helps your users to collaborate with their peers
in other institutions
– size of the fabric matters! (that’s another talk)
• Need to take small steps towards market economics?
– Incentivise partners
– Accommodate fEC
15th January, 2007
15
Questions?
15th January, 2007
16
OGF20 7-11 May 2007
• Manchester, UK
– Manchester Central
• Co-located with 2nd EGEE User Forum
• Hosted by UK e-Science
– local support from the University of Manchester
15th January, 2007
17
Spares
15th January, 2007
18
Reed’s Law, Grids and
Virtual Organisations
Size matters!
15th January, 2007
19
Metcalfe’s Law
• Metcalfe’s law:
– the value of a telecommunications network is proportional to the
square of the number of users
– n2 – n ~ n2
• the number of pair-wise connections enabled by the network
• Benefit to a user grows as the number of other users
– n–1
• Collective value is the number of users (n) multiplied by the
benefit each receives
15th January, 2007
20
Reed’s Law
and Group Forming Networks
David P. Reed, 1999
• Context Magazine article “Weapon of Math Destruction”
• later, “That Sneaky Exponential — Beyond Metcalfe's Law to the
Power of Community Building”
Reed suggested that the value of some networks grows
with the number of (non-trivial) sub-groups that can be
formed from the network participants. This is:
2n – n – 1 ~ 2n
He called these Group Forming Networks, and cited
several examples, including e-Bay.
15th January, 2007
21
Implications of Reed’s Law
Source: D. P. Reed,
That Sneaky Exponential
Value of Network Type
Gain in value by merging two networks
n
(n+m) – (n+m) = 0
n2
(n+m)2 – (n2 + m2) = 2nm
2n
2(n+m) – (2n +2m)
15th January, 2007
If n=m, 2n(2n-2) ~ (2n)2
22
Caveat!
Not all connections are equally valuable to a user, so the value of a network grows more slowly.
Perhaps Metcalfe’s law should be n log n, not n2.
15th January, 2007
23
Grids as GFNs for VOs
InterGrid
Virtual
Research
Environment
s
Virtual
Organisations,
VOMs, CAS
Science
2.0
Reed’s
Law
Science
Gateway
s
Collaboratories
Communit
y Building
Are Grids the Group Forming Networks for
Virtual Organisations?
15th January, 2007
24
Virtual Organisations
re-considered
• Grids and VOs are complex, multi-dimensional networks
– people, networks (of the other kind), resources (machines, data,
applications, services,...)
• I’m being deliberately vague when I talk about the size of such networks
• Glued together by social networks
• Most examples of effective multi-organisational VOs today
– build on established social networks and have long term goals and
strategy
– have significant funding, governance & policy of their own
• These VOs
– need to share data, applications, instruments,...
– sometimes collectively control some (computational) resources
– often have access rights to resources they do not control
• e.g. national HPC services, public data sets
– may or may not have the capacity to construct their own grids
15th January, 2007
25
What is the domain of
facile VO formation?
– single sign-on and interoperable middleware
• have policy, governance, monitoring/accounting/logging, support,
training, documentation, access/account lifecycle procedures...
• things generally not addressed by middleware!
– (almost) sufficient, but limited in size and hence value
• “islands of interoperability”
– larger domains of single sign-on and interoperable middleware
can arise without central governance
– but interoperation is not sustainable without concerted effort
– no-coordinated policy, governance, monitoring, accounting,...
– cost of joining is higher for users; problem resolution is hard
Increasing Size and Value
Consider
• production grids (TeraGrid, EGEE, UK NGS, DEISA,...)
• “Intergrid” or “Grid of grids”
– doesn’t exist yet
• Internet
– necessary infrastructure, but not sufficient
15th January, 2007
26
Size matters!
• NGS is not just about providing resources to end users
• It is also about providing a fabric or framework to enable
collaboration between participating institutions
• View NGS as a Group Forming Network for VOs
• Reed’s Law, even with caveats, tells us that the size of
the GFN matters
• NGS has to
– lower the cost of participation
– expand
– evolve
• More on these later
15th January, 2007
27
VOs: User perspective
• Individual users find it hard to
–
–
–
–
–
learn to use the generic infrastructure
maintain necessary client software
obtain necessary credentials
negotiate access rights
port and/or adapt their applications to (heterogeneous) Grid
environments
– change how they work
• There is a gap between what a Grid infrastructure
provides, and what end users can easily use
• Users need to band together into communities (with
common goals, applications/tools, data)
15th January, 2007
28
VOs: Provider perspective
• NGS told to grow its user base to 3000
– giving smaller and smaller slices of the cake to less
and less expert users simply won’t work
– naïve approaches to user/account management stop
scaling as the numbers of resources and users grow
• NGS can only do so much for any individual
end-user
• NGS needs to start dealing with groups or
communities of users with common needs
– i.e. Virtual Organisations
• NGS will help communities to help themselves
15th January, 2007
29
VOs in NGS
• VOMS (VO Membership Service)
– web-based interfaces for managing membership and roles,
delegated to VO admin
– issues VOMS proxies (GSI proxies dressed up with membership
and role assertions)
• NGS can host VOs in VOMS now
• Full integration with NGS account lifecycle by May 07
– project-based applications mapped to VOs
– NGS resources to publish which VOs they “support”
– NGS partners to get kick-back allocation mapped onto a VO
• More VOMS-aware authorisation – on-going
• VOs can use NGS resources to provision VO services
15th January, 2007
30
What else is NGS doing to help VOs?
• Making NGS Portal software (portlets etc) available for
re-use in community portals
– available for download February 2007
• Can provide directories for installing community software
on NGS resources
• NGS wiki available now for VOs to advertise themselves,
their value-adding services and tools, and recruit
• SRB federation – making it easier for communities with
their own SRB’s to use both
• Deploying a UK GRIMOIRES registry (from OMII) where
community services can be published
– will also register GridSAM instances configured for NGS
resources
• Providing a “Service Hosting Service”
15th January, 2007
31
Some early examples
• BRIDGES portal allows VO members to run tasks (e.g. BLAST
searches)
– users don’t even know they’re using NGS
• NEBC BioLinux
– 100 managed NEBC BioLinux machine situated in community with
value-adding applications and tools
– NGS client tools are being added to NEBC BioLinux distribution, and
some key tools are being extended to use NGS resources for execution
of more computationally intensive tasks
• Computational Chemists are using the Application Hosting
Environment (from OMII) to present certain applications as Web
services
– application services are managed by a few experts for a larger
community
15th January, 2007
32
Interoperation
is a global issue
AIST-GTRC
CSI (JP)
EGEE(EU)
NAREGI (JP)
GridPP(UK)
LCG(EU)
IBM
DEISA(EU)
UniGrids(EU)
common users,
staff & procedures
common
users
Condor(US)
GGF
OSG(US)
Globus(US)
NGS(UK)
common
funding
common
users
TeraGrid(US)
OMII(UK)
NMI(US)
15th January, 2007
33
Tensions
•
NGS must expand
–
–
–
•
To bring in new partners, must make it easy to comply with the MSS.
NGS shows the way  NGS must lead
The bigger we are, the harder it is to evolve
NGS must be a production quality Grid
–
“Operating a production grid means valuing robustness and reliability over fashion”
•
–
•
be part of a Service-Oriented world
provide new features, such as resource brokers, VOMS, service-hosting services,...
as we evolve, need sound migration paths for end-users and providers alike
the more we prescribe in the MSS, the harder it is to expand
NGS must leverage
–
•
The more we invest in policy and procedures to patch gaps in middleware and standards
(e.g. accounting systems, access policies, account lifecycle), the more we become locked in
to obsolescent technology.
NGS must evolve
–
–
–
–
•
true, but taken to extremes, could lead to fatal conservatism
align with UK, European and international efforts  NGS must follow, but what
NGS must be user-oriented
–
–
–
“Don’t be obsessed with middleware and technology. Think about services and capabilities.”
Strong steer from GOSC Board.
Yet we’ve seen that a large domain of interoperability is essential to our mission.
15th January, 2007
34
Claims
•
•
Grids are not yet very effective at supporting VO formation.
Reed’s Law suggests that the long-term value proposition for collaboration
grids depends on how well they facilitate this
– and provides compelling arguments for combining or federating grids
•
Interoperation is a pre-requisite for federation
– standards work and conscious co-operation are essential
•
Gaps in middleware & standards are patched by policy & practice within a grid
– When federating grids, problems re-surface.
•
Already, the VO notion is proving useful to user and provider communities alike
as these scale up
– despite there being almost no tools focused on VO support
•
VOs need to become first-class entities in grids
– Make explicit the consumer-provider relationship between VOs and grids
– VOs need to have global scope – their value is severely diminished when
constrained to a single grid
15th January, 2007
35