"failed to get PBM configuration" causes memory leak.

[tidusstrife5]

Describe the bug
Since the update that released the following change, we have seen the log below being constantly pushed AND the memory usage of the exporter continually ramps up (See screenshot below).

failed to get PBM configuration: get: mongo: no documents in result

To Reproduce
Steps to reproduce the behavior:

1. Use MongoDB 4.4 as a shard cluster
2. Use the collect-all parameter

Expected behavior
Memory is kept within safe boundaries AND/OR PBM config is not activated if it is not expected. (MongoDB 4.4 problem?)

Logs
failed to get PBM configuration: get: mongo: no documents in result

Environment

• Flatcar
• Docker
• MongoDB 4.4 community edition

[idoqo]

Hi @tidusstrife5, thanks for your report - we are aware of this (#924) and are currently working on a fix.