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  1. Core Server
  2. SERVER-48399

Writing config document to "local.system.replset" should not acquire database lock in stronger mode (X).

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      19

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      It seems when the node persists new config in collection "local.system.replset", it takes "local" database lock in stronger mode (X) and PBWM lock in IS mode. This can lead to 2 major side effects.
      1) Since PBWM lock is taken in IS mode, this can block the secondary oplog applier which requires PBWM in X mode. This can result in replication lag. This will be addressed by SERVER-48398
      2) Since it takes "local" database lock in X mode, this can block other local database readers and writers.

      • Mainly, if this node X is the sync source for node Y, then the oplog fetcher of the node Y can be blocked behind the the reconfig via heartbeat thread due to database lock conflict, leading to replication lag.

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              Assignee:
              backlog-server-repl Backlog - Replication Team
              Reporter:
              suganthi.mani Suganthi Mani
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                Updated: