Download Aspect Meaning Representation

THE US NATIONAL VIRTUAL OBSERVATORY
Do we have our heads
in the cloud?
Matthew J. Graham (Caltech, NVO)
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
1
The Cloud is…
• An elephant in a room of blind men:
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SaaS
Utility computing
Web services
Platform as a service
Managed service provider
Service commerce platform
Internet integration
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fast
scalable
resilient
available
• All those things that the Grid promised but turned out not to be:
• A virtualised notion of distributed computation, storage and
communication over unlimited resources
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
2
Virtualisation
• Virtual workspaces:
– An abstraction of an execution environment that can
be made dynamically available to authorized clients by
using well-defined protocols
– resource quota (e.g. CPU, memory share)
– software configuration (e.g. O/S, provided services)
• Implement on Virtual Machines (VMs):
– abstraction of a physical host machine
– hypervisor intercepts and emulates instructions from
VMs and allows management of VMs
– VMWare, Xen, etc.
• Provide infrastructure API
– Plug-ins to hardware/support structures
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
3
Different types of cloud
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Amazon:
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Google:
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Microsoft:
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Yahoo:
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Sun
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Zoho
Adobe (AIR)
Commercial providers:
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Problem becomes availability of the right type of environment (hypervisor)
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“computing in the cloud”
EC2 (with S3, SQS and SimpleDB)
Use Xen VMs
Images, Instances and Security
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Apps: Python module/API (with BigTable)
Working also with IBM (Blue Cloud)
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Windows Live
Silverlight
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Pipes
Working with Computational Research Laboratories (CRL)
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Project Hydrazine (JavaFX)
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SalesForce
FlexiScale from XCalibre/Virtual Iron: “cooler than EC2”
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
4
Globus Workspace
Metadata
instance
Create()
Deployment
request
Inspect & manage
Notify
Workspace
Factory Service
Authorize
& instantiate
Workspace
Service
Workspace
Resource Instance
Deployment RP
• Abstracts hyperviser using WSRF
• Back-end implementation using Xen VMs
on a variety of “science clouds”
Contains GLOBUS
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
5
Clouds live in the Sky
• A lightweight abstraction layer a la
VOSpace
• Resource oriented
• Data and services both treated as
first-class entities
• Uses UWS interface for resource
management
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
6
Identifiers and representations
• Use XRIs to identify all resources
including computational results:
xri://@!the.sky/myService/(+<aspect>)
• Different representations (in RDF)
returned dependent on resource aspect:
Aspect
Meaning
Representation
object
Data object
VOSpace <node>
image
Service image
VOResource
instance
Service instance
UWS metadata
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
7
Use case
• I have a data analysis service:
ivo://nvo.caltech/MyService
• Upload bytes of a VM image:
xri://@!the.sky/MyService/(+object)
• Create service instance:
HTTP POST to http://@!the.sky/MyService/(+instance)
Returns xri://@!the.sky/MyService/1234
• Commit instance to execution:
HTTP POST to http://@!the.sky/MyService/1234/(+instance)/quote
• Define computation:
xri://@!the.sky/MyService/1234+
data@xri://@!the.sky/MyData/myTable1+
params@xri://@!the.sky/MyData/myParam1
• Link to results:
xri://@!the.sky/MyData/myResults1
• Retrieve bytes:
xri://@!the.sky/MyData/myResults1/(+object)
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
8
Is this just blue sky thinking?
• “There’s probably a future business in
offering an abstraction layer between
cloud computing services”
• “The missing element is cloud
abstraction”
• Proof-of-concept system based on
VOSpace, UWS and a resource-oriented
middleware layer in front of EC2 (and
Google Apps)
IVOA Trieste: Grid & Web Services/AstroRG
20 May 2008
9