# MongoDB Instance Summary dashboard shows "No data" for mongos services on PMM 3.6.0

**URL:** <https://forums.percona.com/t/mongodb-instance-summary-dashboard-shows-no-data-for-mongos-services-on-pmm-3-6-0/40383>\
**Category:** Percona Monitoring and Management (PMM)\
**Tags:** mongodb\
**Created:** [March 20, 2026, 12:55pm UTC](https://forums.percona.com/t/mongodb-instance-summary-dashboard-shows-no-data-for-mongos-services-on-pmm-3-6-0/40383 "2026-03-20T12:55:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![helloyeops](https://avatars.discourse-cdn.com/v4/letter/h/278dde/32.png) [@helloyeops](https://forums.percona.com/u/helloyeops)\
**Post date:** [March 20, 2026, 12:55pm UTC](https://forums.percona.com/t/mongodb-instance-summary-dashboard-shows-no-data-for-mongos-services-on-pmm-3-6-0/40383/1 "2026-03-20T12:55:32Z")

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## Description:

The MongoDB Instance Summary dashboard in PMM 3.6.0 shows “No data” on several panels when a mongos service is selected. The `Service Name` dropdown includes mongos services, so users expect data to appear, but the panel queries only use mongod-specific metrics (`mongodb_mongod_metrics_document_total`, `mongodb_mongod_metrics_query_executor_total`) that are not available on mongos instances.

Additionally, when using `--enable-all-collectors` on mongos via the Percona Operator’s `mongosParams`, the `indexstats` collector queries `$indexStats` across all shards, causing the same collection+index combination to be returned multiple times (once per shard) with identical labels. This results in duplicate metric errors for `mongodb_indexstats_accesses_ops`.

## Steps to Reproduce:

Issue 1: Instance Summary “No data” on mongos

1. Deploy a sharded MongoDB cluster using Percona Operator with PMM enabled

2. Navigate to MongoDB \> Instance Summary dashboard

3. Select a mongos service in the `Service Name` dropdown

4. Observe “No data” on Document Operations and Query Efficiency panels

Issue 2: `--enable-all-collectors` duplicate metric error on mongos

1. Set `mongosParams: "--enable-all-collectors"` in the PerconaServerMongoDB CR

2. Wait for mongos pods to restart with the new PMM config

3. Check pmm-client container logs: `kubectl logs <mongos-pod> -c pmm-client`

4. Observe repeated duplicate metric errors

## Version:

1. PMM Server: 3.6.0
2. PMM Client: 3.6.0 (percona/pmm-client:3.6.0)
3. Percona Server for MongoDB: 8.0.8-3
4. Percona Operator for MongoDB: 1.21.1
5. Platform: AWS EKS

## Logs:

pmm-client container log from mongos pod (Issue 2):

```auto
level=ERROR source=http_error_logger.go:47 msg="error gathering metrics:" 
error="[from Gatherer #2] collected metric \"mongodb_indexstats_accesses_ops\" 
{ label:{name:\"cl_role\" value:\"mongos\"} 
  label:{name:\"collection\" value:\"lookup_franchise_no_stage_2026_01_09\"} 
  label:{name:\"database\" value:\"cdp\"} 
  label:{name:\"key_name\" value:\"hashed_id_idx\"} 
  untyped:{value:0}} 
was collected before with the same name and label values" 
total_errors=36

```

This error repeats for every collection/index combination across all shards (36 errors per scrape cycle).

## Expected Result:

Issue 1:

- Instance Summary should either filter mongos services out of the Service Name dropdown, or conditionally switch queries to mongos-compatible metrics (e.g., `mongodb_mongod_op_latencies_*` which works on both mongod and mongos), or hide panels that are not applicable for mongos.

Issue 2:

- `--enable-all-collectors` on mongos should work without duplicate metric errors. The exporter should either deduplicate index stats from multiple shards, or add a `shard` label to differentiate them.

## Actual Result:

Issue 1:

- Document Operations panel shows “No data” because it queries `mongodb_mongod_metrics_document_total` which is mongod-only.

- Query Efficiency panel shows “No data” for the same reason.

- Other panels like Operation Latencies work correctly because `mongodb_mongod_op_latencies_*` is collected from mongos as well.

Issue 2:

- 36 duplicate metric errors per scrape cycle, one for each collection+index combination across shards.

- The indexstats collector on mongos queries all shards via `$indexStats`, returning the same collection+index from multiple shards with identical labels, causing the Prometheus collector to reject duplicates.

## Additional Information:

- Cluster topology: 3 shards x 3 replset nodes + 3 mongos + 3 config servers

- The Router Summary dashboard correctly displays mongos metrics. This issue is specific to Instance Summary.

- Current workaround for Issue 2: only use `--enable-all-collectors` on `mongodParams`, not `mongosParams`:

yaml

```auto
pmm:
  enabled: true
  mongodParams: "--enable-all-collectors --environment=prod"
  mongosParams: "--environment=prod"

```

- Some `mongodb_mongod_*` metrics are collected from mongos (e.g., `op_latencies`), while others are not (e.g., `metrics_document_total`). This naming inconsistency makes it difficult to determine which metrics are available for mongos without trial and error.

---

<div class="post-metadata">

**Author:** ![helloyeops](https://avatars.discourse-cdn.com/v4/letter/h/278dde/32.png) [@helloyeops](https://forums.percona.com/u/helloyeops)\
**Post date:** [March 21, 2026, 12:22pm UTC](https://forums.percona.com/t/mongodb-instance-summary-dashboard-shows-no-data-for-mongos-services-on-pmm-3-6-0/40383/2 "2026-03-21T12:22:15Z")

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```
mongosParams: "--enable-all-collectors --disable-collectors=indexstats --environment=stage"

```

It worked for me.

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<div class="post-metadata">

**Author:** ![Ivan\_Groenewold](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/ivan_groenewold/32/6299_2.png) [@Ivan\_Groenewold](https://forums.percona.com/u/Ivan_Groenewold)\
**Post date:** [March 23, 2026, 11:26am UTC](https://forums.percona.com/t/mongodb-instance-summary-dashboard-shows-no-data-for-mongos-services-on-pmm-3-6-0/40383/3 "2026-03-23T11:26:35Z")

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glad to hear it’s sorted out