Repeatedly creating and dropping the same TTL index causes the TTL job to run multiple times within a single cycle

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    • Type: Bug
    • Resolution: Unresolved
    • Priority: Major - P3
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    • Affects Version/s: 8.3.4
    • Component/s: None
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    • Storage Execution
    • ALL
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      db.createCollection("coll");
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, {expireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });

      Creating and dropping the index very quickly, and then change the log level.

      db.setLogLevel(1);

      more mongo.log | grep -i a_1 | grep 22533

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      db.createCollection("coll"); db.coll.createIndex({a:1}, { expireAfterSeconds: 1 }); db.coll.dropIndex({a:1}); db.coll.createIndex({a:1}, { expireAfterSeconds: 1 }); db.coll.dropIndex({a:1}); db.coll.createIndex({a:1}, {expireAfterSeconds: 1 }); db.coll.dropIndex({a:1}); db.coll.createIndex({a:1}, { expireAfterSeconds: 1 }); Creating and dropping the index very quickly, and then change the log level. db.setLogLevel(1); more mongo.log | grep -i a_1 | grep 22533
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      In the latest version 8.3.4:

       

      db.createCollection("coll");
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, { expireAfterSexpireAfterSeconds: 1 });
      db.coll.dropIndex({a:1});
      db.coll.createIndex({a:1}, { expireAfterSeconds: 1 });

      db.setLogLevel(1);

      Repeatedly creating and dropping the TTL index causes the TTL index to run for multiple rounds within the same cycle.

      The expected behavior is that it runs only once per cycle.

       

       

      more mongo.log | grep -i a_1 | grep 22533

       

        1. image-2026-06-24-10-53-55-732.png
          image-2026-06-24-10-53-55-732.png
          919 kB

            Assignee:
            Unassigned
            Reporter:
            Chao Yin (EXT)
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            Watchers:
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              Created:
              Updated: