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ProposedMetricPacketEnhancements

Daniel Pocock edited this page Feb 12, 2015 · 3 revisions

Proposed enhancements to the XDR UDP metric packets

High-level requirements and possibilities

  • include a source UUID representing the source host
  • security
    • include an authentication digest similar to the 4 byte signature on SRTP packets
    • encryption of the packets
  • network efficiency
    • combine multiple metric values into a single UDP packet up to the permitted MTU
  • metric namespace
    • support for arrays of metrics (e.g. cpu[0], cpu[1])
    • support for metric hierarchy/tree structure
    • possible use of a UUID instead of a metric name for each metric
  • timestamp
    • include the timestamp when the metric was sampled (which may be earlier than the moment it was transmitted on the wire)

Strategy

  • backwards compatibility:
    • new version of gmond should be able to receive packets from the current version as well as receiving the new format
    • it should be possible to represent the data in the same XML schema (so that gmetad and other in-house scripts for parsing the XML will still work)
    • it may be possible to offer an enhanced XML schema to support the new features, and a config file option should exist in gmond.conf to select new or old XML output format
  • not all features will be implemented immediately
    • e.g. the packet format may reserve space for an authentication digest, but gmond might not have any code for generating such a value until further in the future