2022.03.28

• Discussion
  • Need to update documentation and make sure that when someone googles for LDMS and related they get something appropriate returned
  • "News" should not refer to something that happened a year ago!!!
• Presentation
  • LDMS_V_LIST and LDMS_V_RECORD
    • Description
    • Use cases
    • API Overview
  • Comparison of samplers converted to use lists and records
    • procnetdev
    • procstat
• Discussion of pros and cons of converting old samplers to use lists and records vs. writing new versions of samplers
• Metric List and Records:
  • Schema with varying sizes and metric sets that can have varying numbers of entities in order to accommodate varying systems and user-specific metrics.
  • List: linked-list, LDMS list can be of different value types.
    • In the future we would like to impose "same-type" restrictions because the storage plugins in LDMSD do not support mixed-type lists.
    • While the system can handle it, it is highly not recommended for the consumer
    • Any entry can also be a list (list of lists)
    • Lists are dynamically allocated from the metric's "heap"
    • Heap follows static data: the meta data and the data itself. The meta data carries info on the type of data. Data follows the meta data and contains the metric values and the heap.
  • Records:
    • Analogous to 'struct' in C
    • List of Record API in the header files
    • The ability to allocate records and manipulate the member data.
    • Able to add record instances, access record in the list and access record members.
    • Note: A record cannot contain a list.
  • Discussion Notes:
    • LDMS creates the heap while LDMSD creates the schema.
    • Records should be either all JSON or not. Currently a mix.
• Next meeting:
  • How does the store handle and interact with the Lists and Records.