Information breakout

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Information breakout
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Things what we did

• What is the difference between a registry and a
  catalog?
• What do we mean by naming?
• What does OGSA define?
• Using projects represented, try to categorise and
  identify common themes

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Naming and Registries
Project OGSA-DAI (OGSI) DAIS (WS-RF) MDS2 (pre-WS) MD4 (WS-RF) rGMA jGMA EGEE DM UDDI
Query API GT3 SGR XPath LDAP Globus MDS rGMA API SQL jGMA API SQL EGEE RLS UDDI
Human XML CIM ? GLUE schema XML thing GLUE schema GLUE schema CIM Logical filenames (EGEE) Name Categorisation taxonomies
GT3 LDAP WS-RF, WS-I WSAgree MySQL JDBC / XMLDB ? e.g. UDDI4J
Abstract LDAP map of GLUE schema ? Table GUID TModel (internal)
GT3 LDAP WS-RF MySQL JDBC ? e.g. UDDI4J
Address GSH EPR inc ReferenceProperty UNIX pathname WS-RF ReferenceProperty EPR extra info Endpoint as URL Physical Filename URL
Output API GT3 rGMA API jGMA API UDDI
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Things to note (1)

• There is no reference framework to allow us to
  compare our registries / catalogs
• The definition of the naming layers is confused
• The standards used by the implementations seem to
  be based on when they were built
• GLUE schema
• LDAP
• ServiceGroupRegistries
• WS-RF

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Things to note (2)

• No projects are using UDDI
• But ETF in UK is deploying UDDI for registering
  services
• This is also the UK Grid Strategy
• We are moving towards using databases to maintain
  persistence
• The GLUE Schema does not do everything
• Everyone has extended it to suit their purpose
• There needs to be a way of capturing whats good
  in GLUEextns in CIM

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Other things we should look at

• How do these groups define registries and naming?
• DNS
• ebXML
• DAML

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What specs past WS-I

• What is the split between registry and catalogs?
• Naming
• Registry
• Catalogs
• UDDI
• Fine for static data
• Not good when you have high update rates

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Registry

• WS-ServiceGroup
• WS-ResourceProperties
• WS-ResourceLifetime
• To define lifetime of entries?
• WS-Notification
• WS-BaseNotification
• WS-BrokeredNotification
• WS-Topics

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• MDS uses
• WS-ServiceGroup
• ResourceProperty
• ResourceLifetime

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rehistry

• One registry may be used for many purposes but
• Most have specific requirements

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rGMA Registry

• Two registry functionalities
• Registry for metadata
• Metadata about producers and consumers
• Map attribute to an information source
• Represented as GLUE Schema extensions
• Handles represented as URIs
• Will be a WebService EndPoint
• Update rate is very important
• SOAP over HTTP to do messages

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Important Questions about registries

• Where is data kept?
• How are the schemas defined?
• How are the interfaces defined?
• Whats important for the users of a registry?
• What do you use it for?
• Metadata
• Naming
• Is a catalog a registry which maps names?
• Jenny
• RLS takes a logical name and maps to physical
  name
• MDC takes a set of attributes and maps it to a
  logical (physical) name

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• Discovery
• Finding something based on metadata
• OGSA defines naming in three levels
• Human defined name schemes
• Could include arbitary metadata
• Abstract name
• Probably unique
• Concrete Addresses
• The physical location

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• OGSA-DAI
• ServiceGroupRegistry
• Resolve metadata information to ServiceHandles
• No GSH-gtGSR mapping (abstract-gtphysical) because
  of GT3 optimisation
• Represented as DAIS specific schema

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• Would like to map from metadata to abstract names

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WS-RF

• WS-Addressing WS-RenewableReferences defines a
  slightly different two layers

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DNS

• What can we learn from DNS?

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MDS2

• Human Form GLUE schema (node-mem)
• Abstract Form LDAP mapping of GLUE schema
  returns a Value (12.3.4.2.info-hostname)
• Address Fully qualified name (e.g. of attached
  disk)

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DAIS2

• Human My genome db
• Abstract URN dais//12345
• Address WS-RF EPR ResourceProperty