When multiple operations are executed on an async mongo client just after it has been created, a single operation may be lost, and no callback is fired or timeout occurs. This may lead to execution timeout errors in production code and may affect all async mongo users that use the client directly after initialisation.

The attached example attempts to demonstrate the behavior. When the commented sleep() is uncommented, the example should always succeed. Otherwise, the example should fail most of the time with a "1 remaining operations" message. Note that sometimes, this example succeeds, please run it multiple times when the problem is not immediately present.