What problem are you facing?

When our server (temporarily) reaches 100% CPU due to a brief activity spike MongoDB will throw a (Mongo)PoolClearedError.

During this time, any changes (insert/update/remove) received are not reflected in the database, which is fine. However they are also not processed AFTER the server recovers (without a hard process restart or anything).

What driver and relevant dependency versions are you using?

MongoDB Node.js Driver 4.16, although looking at the code, I expect this issue to be present in 6.x as well.

MongoDB 6.0.12

Steps to reproduce?

Trigger a (Mongo)PoolClearedError while the waitQueue is being processed, and some or all of the entries in the waitQueue will not be processed, even after the server reconnects.

Possible cause

I think this problem may be caused by this check in server.ts:

          if (!(err instanceof PoolClearedError)) {
            this.handleError(err);
          }

It seems like any error besides the PoolClearedError is handled, but PoolClearedErrors are not?