collstats metrics for shard cluster is incomplete

[abelite-fang]

Describe the bug We are using mongodb_exporter on our shard cluster via SRV record, the collstats metrics like mongodb_collstats_storageStats_count{} return single shard count, and there is no label to identify which shard it is.

To Reproduce Steps to reproduce the behavior:

1. Parameters:

   
   serviceMonitor:
   enabled: true
   interval: 10s
   scrapeTimeout: 9s
   additionalLabels:
   release: prometheus-operator
   metricRelabelings:
   - targetLabel: cl_name
     replacement: core

existingSecret: name: "prometheus-mongodb-exporter" key: "mongodb-uri"

extraArgs:

• --collector.indexstats
• --collector.collstats
• --collector.collstats-limit=0
• --collect-all=true
• --discovering-mode=true
• --no-mongodb.direct-connect

2. connection string set to SRV record, and designate collection label to a sharded collection, exporter will only return single shard collstats.

Expected behavior Expect to have collstats (e.g. document counts, logical data size, etc.) for each shard on a sharded cluster, identify by shard name (replicaset name) or any other label.

Logs no relevance error log.

Environment

• environment: Kubernetes (EKS)
• MongoDB Atlas (managed), version: 5.0.25
• helm chart: prometheus-community/prometheus-mongodb-exporter version 3.5.0
• image: percona/mongodb_exporter:0.40.0

[igroene]

the rs_nm label should be useful to know which shard it belongs to