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  1. Core Server
  2. SERVER-40123

Transaction diagnostics should not report upconverted readConcern

    • Type: Icon: Bug Bug
    • Resolution: Duplicate
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: Replication
    • None
    • ALL
    • Repl 2019-06-17, Repl 2019-07-01, Repl 2019-07-15, Repl 2019-07-29, Repl 2019-08-12, Repl 2019-08-26

      Transaction diagnostics report that all transactions execute with readConcern level snapshot, since originally we intended to upconvert the readConcern to snapshot for all single replica set transactions. However, this is false, since as we saw in SERVER-35821, transactions with readConcern level majority and local do not execute with snapshot isolation. This difference will be more pronounced with multi-shard transactions, where we only select the same read timestamp across shards if the requested readConcern level is snapshot. Transaction diagnostics should now report the requested readConcern level.

      There is a question of what to report when no readConcern was specified, since we intend to change the default readConcern from local to (speculative) majority in SERVER-34837. We could report no readConcern for these transactions, since no readConcern was requested.

            Assignee:
            samy.lanka@mongodb.com Samyukta Lanka
            Reporter:
            tess.avitabile@mongodb.com Tess Avitabile (Inactive)
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              Created:
              Updated:
              Resolved: