Hi there,

We're using a custom application to collect and store the slow queries on our MongoDB deployments. We're using the `appName` to identify the applications making slow queries.

We're noticing missing `appName` on some queries. We did many tests on our side to isolate and replicate the issue :

• That's not query specific : the same query, coming from the same application, can be reported with and without the query
• On this application, we're 100% sure the `appName` is set
• The issue is not coming from our application : the `appName` is missing on the profiler too (I can share the profiler output privately)

We didn't find any related issue on the changelogs.

We're noticing the issue from different drivers : `globalsign/mgo`, official NodeJS and official PHP.

Can you tell us if we're missing something, or is there an issue on mongod side ? FYI, we noticed the issue only on our sharded clusters. As our replica set are less used, and less slow queries are reported on them, we don't know if there is a similar problem or not.

Thanks,

Anthony