Uploaded image for project: 'Core Server'
  1. Core Server
  2. SERVER-59689

Add downgrade routines for balancer fields upon setFCV < 5.0

    XMLWordPrintable

    Details

    • Type: Task
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Backlog
    • Component/s: None
    • Labels:
      None
    • Sprint:
      Sharding EMEA 2021-10-04, Sharding EMEA 2021-10-18, Sharding EMEA 2021-11-01

      Description

      When the user uses the new setCollectionAutoSplitter command, we perform a durable format change. Two new fields to the collection metadata in config.collections and cache.collections are added, as well as a new flag in config.collections

      The new balancer chunk merge routine will not use any new internal commands, so should not need any precautions.

      On performing a downgrade to any version smaller than 5.0 we must remove newly added fields, since 4.4 parses the collection metadata with the strict: true option in the IDL file.

      Upon downgrade to 4.4 or earlier, config.collections and cache.collections documents will be updated accordingly:

      • The no autosplit (noAutoSplit) field will be removed
      • The per collection max chunk size (maxChunkSizeBytes) field will b

        Attachments

          Activity

            People

            Assignee:
            simon.gratzer Simon Gratzer (Inactive)
            Reporter:
            simon.gratzer Simon Gratzer (Inactive)
            Participants:
            Votes:
            0 Vote for this issue
            Watchers:
            2 Start watching this issue

              Dates

              Created:
              Updated: