Network Measurement Schema Version 2

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Network Measurement SchemaVersion 2
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Schema V2

• Key goal extensibility
• Break representation of performance measurements
  down to basic elements
• Use the GGF to standardize measurement schemata
• Promote sharing of data via well-defined
  representation
• Overlap with with IPPM should be minimal
• Possibly some overlap with metric registry
• Essential breakdown Data and Metadata

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Schema Basic Elements - Metadata

• Subject
• The measured/tested entity
• Characteristic/Event Type (Verb)
• What type of measurement, value or event occurred
  
• Parameters (Adjectives and Adverbs)
• How, or under what conditions, did this event
  occur?

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Schema Basic Elements - Data

• Some sort of value Datum
• Existence of an event might point to a case where
  there is no value (boolean)
• Time
• A tricky issue
• Must be extensible since even agreement of the
  right structure is not easy

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A Message
Message
Message
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An Object Store
Store
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A Data is Linked to A Metadata
Metadata ltIdgtsomeIdlt/idgt
Data ltmetadataIdRefgt someId lt/metadataIdRefgt
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A Metadata may be linked to another
Metadata ltIdgtsomeIdlt/idgt
Metadata ltIdgtsomeOtherIdlt/Idgt ltmetadataIdRefgt
someId lt/metadataIdRefgt
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Schema Namespaces

• All measurements have some sort of Data and Time
• All measurements can be described by the Metadata
  identifying who, what and how
• The specific structures of the the Data and
  Metadata elements depend on the measurement
• V2 approach Use Data and Metadata elements and
  vary the namespaces of the specific elements

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Schema Namespaces - 2

• Why encode the event type in the namespace?
• Some components can pass Data and Metadata
  elements through without understanding their
  specific structure
• Allow in an implementation to decide whether it
  supports a specific type of data or not
• Allows validation based on extended
  (namespace-specific) schemata

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Schema Namespaces and Extensibility

• One key to extensibility is the use of hierarchy
  with delegation
• OIDs in the IETF management world
• The NM-WG has a hierarchy of Characteristics
• Natural starting point
• However, not all tools are cleanly mapped onto
  the Characteristic space
• Often a matter of some debate

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Schema Namespaces and Extensibility - 2

• Tools namespace addresses this
• Some top-level tools
• ping, traceroute
• Easy to add new tools in organization-specific
  namespaces
• We need to discuss a repository for the
  namespaces and schema extensions
• The Grid Performance Event Repository
• GPERs!

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Schema Representation

• RelaxNG schema language
• Specifies a compact syntax that isnt even XML!
• There is an XML one
• Has features that make it a superior schema
  definition language
• But we translate into XML Schema
• Thats what the tooling generally expects

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Schema Walkthru

• nmbase.rnc
• nmtime.rnc
• nmtopo.rnc

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Schema Walkthru 2

• Characteristic/tool-specific versions bring base
  elements into a new namespace
• ping.rnc
• iperf.rnc
• traceroute.rnc
• utilization.rnc

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Instance Walkthru

• Example Instances