exporter produces mongodb_dbstats_raw_xxxxxx metrics with a very very long names

[WojciechKuk]

Describe the bug
my mongodb_exporter produces prometheus metrics with very long names (name)

mongodb_dbstats_raw_xxxxxx_views
mongodb_dbstats_raw_xxxxxx_totalSize
mongodb_dbstats_raw_xxxxxx_totalFreeStorageSize

in the place of "xxxxxxx" there is a very long list of all replicas.

i.e.
mongodb_dbstats_raw_mongodb_name_of_replica_one_portnumber_mongodb_name_of_replica_one_portnumber_mongodb_name_of_replica_two_portnumber_mongodb_name_of_replica_three_portnumber_mongodb_name_of_replica_four_portnumber_mongodb_name_of_replica_five_portnumber_mongodb_name_of_replica_six_portnumber_mongodb_name_of_replica_seven_portnumber_mongodb_name_of_replica_eight_portnumber_mongodb_name_of_replica_nine_portnumber_mongodb_name_of_replica_ten_portnumber_totalFreeStorageSize

To Reproduce

1. set up mongodb sharded cluster with many mongos instances
2. run mongodb_exporter

Expected behavior

replicas names shouldn't be used in metric names (it's very dangerous for prometheus/victoriametrics name index - especially when replicas are in k8s, and have POD names with big cardinality)
If it's necessary, names should be added as labels.

[BupycHuk]

Hello @WojciechKuk,
I tried to reproduce this behavior, but couldn't. Can you please share a few more details?

1. What version of mongodb is used?
2. What is topology of your cluster?
3. What version of mongodb_exporter is used?
4. What flags were enabled?
5. Which instance was monitored and provided these metrics?