An XML Schema for NMWG

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An XML Schema for NMWG

• Yee-Ting Li, UCL

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Metrics

• All results from Network Monitoring stored in
  some format
• Usually as a flat text file
• Could store in a table in a Database
• Need to convey the meaning the data and the
  format in which it is kept (meta data etc)
• XML!

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NMWG

• Working Group at GGF
• Focuses on describing metrics (characteristics)
  for use in Grid Environments
• How to make more use of Network information
• Encompasses work from IPPM
• Two documents planned
• Characteristics and measurements document
• Describes the structure and relationship of
  metrics (characteristics) against each other
• Hierarchy of characteristics
• Tools Document
• Maps tools such as iperf and ping to specific
  points on the characteristic heirachy

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NMWG Overview

• Similar to IETF IPPM
• But focuses more on how to use the metric rather
  than measure it
• Defines singleton and statistical characteristics
• Singletons are a specific instance of a
  characteristic
• Statistical characteristics are formed as a
  result of 2 or more singletons
• Defines classes of characteristics that describe
  WHAT you are measuring
• e.g. bandwidth, delay etc.
• Uses a hierachy to give structure and
  relationships to characteristics
• Defines a Measurement Methodology to describe
  HOW to measure the characteristics
• Defines samples of data and their inherent
  sampling patterns

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NMWG Overview

• Results gathered into an Observation
• Realised by a Measurement Methodology
• Which measures a Characteristic
• Which describes a Network Entity

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NMWG Overview
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An XML Schema for NMWG

• XML Schemas describe the structure and content of
  XML document
• Document language to describe virtually anything!
• Uses meta data to give context to documents
• Industrial standard
• Cross platform
• nothing more than a text file
• Extensible and Flexible
• Used throughout Web Services and OGSA
  technologies

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NMWG Schema Goal

• To be able to fully describe network
  metrics/characteristics
• In complete and extensible way
• Able to store as much information as required
• Able to have as little information as required
• To be used in a real system with real results
• Capable to describing WHAT a tool measures and
  HOW and WHERE
• Focusing actually implementing what the NMWG
  document says and doesnt say
• With view on actually using it to retrieve
  results
• As a results doesnt always exactly match what
  NMWG says/suggests ?

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NMWG Schema - Overview

• Measurement Methodology is root
• Used to describe the application used to gather
  the results
• The network it is conducted on
• The results (observations) of the characteristics

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NMWG Schema - measurementMethodology
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NMWG Schema - Characteristics
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NMWG Schema - observationSample

• Tried to incorporate method of describing more
  than one observation at once
• When we retrieve historical information of the
  bandwidth for the last month
• May singleton values as well as statistical
  values
• Collate all ping values for last year!
• Some tools may report more than one
  characteristic
• Eg ping 2WD and loss, traceroute rtt and path,
  pipechar capacity and path etc.

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NMWG Schema - observationSample
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NMWG Schema - Example

• Ping
• ltXML Spy/gt

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NMWG Schema - Example

• Iperf
• ltXML Spy/gt

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NMWG Schema - Example

• Traceroute
• ltXML Spy/gt

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NMWG Schema - Example

• pipechar
• ltXML Spy/gt

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Summary

• A useable implementation of XML Schema for
  Network Monitoring
• Can report single observations or a group of
  observations in a single document
• Demonstrated suitability for most common
  monitoring tools
• Easily extended to most tools
• Also includes non-network information that may
  contribute to poor network performance
• Host configuration, kernel parameters etc.
• However doesnt quite fit into NMWG framework
• Needs further refinement of both the Schema and
  what NMWG define