Failed to restart arbiter after arbiter generates system.profile in admin database

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    • Type: Bug
    • Resolution: Works as Designed
    • Priority: Major - P3
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    • Affects Version/s: 6.0.24, 8.0.11
    • Component/s: None
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      • mongodb version: v8.0.11
      • set up a PSA replicaset with user and authentication
      • set up operationProfiling in arbiter node (which will generate slow query very easily)

      ```
      operationProfiling:
          mode: slowOp
          slowOpThresholdMs: 0
      ```

      • log in the arbiter directly with mongosh
      • try to restart the arbiter, and it fails
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      mongodb version: v8.0.11 set up a PSA replicaset with user and authentication set up operationProfiling in arbiter node (which will generate slow query very easily) ``` operationProfiling:     mode: slowOp     slowOpThresholdMs: 0 ``` log in the arbiter directly with mongosh try to restart the arbiter, and it fails
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      When opens slow query profiling on an arbiter, once the system.profile collection in admin database has been generated, the arbiter will fail to restart.

      The diagnostic log reports the featureCompatibilityVersion document is missing.

      {"t":\{"$date":"2025-07-14T15:56:23.894+08:00"},"s":"F", "c":"COMMAND", "id":40652, "ctx":"initandlisten","msg":"Unable to start up mongod due to missing featureCompatibilityVersion document. Please run with --repair to restore the document."}
{"t":\{"$date":"2025-07-14T15:56:23.894+08:00"},"s":"F", "c":"ASSERT", "id":23091, "ctx":"initandlisten","msg":"Fatal assertion","attr":\{"msgid":40652,"file":"src/mongo/db/commands/feature_compatibility_version.cpp","line":647}}
{"t":\{"$date":"2025-07-14T15:56:23.894+08:00"},"s":"F", "c":"ASSERT", "id":23092, "ctx":"initandlisten","msg":"\n\n***aborting after fassert() failure\n\n"}

      From the code

      FeatureCompatibilityVersion::fassertInitializedAfterStartup` in src/mongo/db/commands/feature_compatibility_version.cpp

```

    // Fail to start up if there is no featureCompatibilityVersion document and there are
    // non-local databases present.
    if (!fcvDocument.isOK() && nonLocalDatabases) {
        LOGV2_FATAL_NOTRACE(40652,
                            "Unable to start up mongod due to missing featureCompatibilityVersion "
                            "document. Please run with --repair to restore the document.");
    }```

      nonLocalDatabases comes ture, due to the system.profile collection in admin database.

            Assignee:
            Jeffrey Ho
            Reporter:
            mingtotti N/A
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              Created:
              Updated:
              Resolved: