feat: add query telemetry

CHANGELOG.md

@@ -41,6 +41,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 * (cli) [#12028](https://github.com/cosmos/cosmos-sdk/pull/12028) Add the `tendermint key-migrate` to perform Tendermint v0.35 DB key migration.
 * (query) [#12253](https://github.com/cosmos/cosmos-sdk/pull/12253) Add `GenericFilteredPaginate` to the `query` package to improve UX.
+* (telemetry) [#12405](https://github.com/cosmos/cosmos-sdk/pull/12405) Add _query_ calls metric to telemetry.
 
 ### Improvements
 

baseapp/abci.go

@@ -388,6 +388,9 @@ func (app *BaseApp) Query(req abci.RequestQuery) (res abci.ResponseQuery) {
 		req.Height = app.LastBlockHeight()
 	}
 
+	telemetry.IncrCounter(1, "query", "count")
+	telemetry.IncrCounter(1, "query", req.Path)
+
 	// handle gRPC routes first rather than calling splitPath because '/' characters
 	// are used as part of gRPC paths
 	if grpcHandler := app.grpcQueryRouter.Route(req.Path); grpcHandler != nil {

docs/core/telemetry.md

@@ -7,16 +7,17 @@ order: 10
 Gather relevant insights about your application and modules with custom metrics and telemetry. {synopsis}
 
 The Cosmos SDK enables operators and developers to gain insight into the performance and behavior of
-their application through the use of the `telemetry` package. The Cosmos SDK currently supports
-enabling in-memory and prometheus as telemetry sinks. This allows the ability to query for and scrape
-metrics from a single exposed API endpoint -- `/metrics?format={text|prometheus}`, the default being
-`text`.
+their application through the use of the `telemetry` package. To enable telemetrics, set `telemetry.enabled = true` in the app.toml config file.
+
+The Cosmos SDK currently supports enabling in-memory and prometheus as telemetry sinks. In-memory sink is always attached (when the telemetry is enabled) with 10 second interval and 1 minute retention. This means that metrics will be aggregated over 10 seconds, and metrics will be kept alive for 1 minute.
+
+To query active metrics (see retention note above) you have to enable API server (`api.enabled = true` in the app.toml). Single API endpoint is exposed: `http://localhost:1317/metrics?format={text|prometheus}`, the default being `text`.
+
+## Emitting metrics
 
 If telemetry is enabled via configuration, a single global metrics collector is registered via the
 [go-metrics](https://github.com/armon/go-metrics) library. This allows emitting and collecting
-metrics through simple API calls.
-
-Example:
+metrics through simple [API](https://github.com/cosmos/cosmos-sdk/blob/v0.46.0-rc1/telemetry/wrapper.go). Example:
 
 ```go
 func EndBlocker(ctx sdk.Context, k keeper.Keeper) {