feat: add query telemetry (backport #12405) (#12463)

* feat: add query telemetry (#12405)

Closes: #12333

---

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- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

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- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
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- [ ] manually tested (if applicable)

(cherry picked from commit f70b67fc91)

* Changelog fix

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

CHANGELOG.md

@@ -37,6 +37,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### Features
+
+* (telemetry) [#12405](https://github.com/cosmos/cosmos-sdk/pull/12405) Add _query_ calls metric to telemetry.
+
 ## [v0.46.0-rc2](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.46.0-rc2) - 2022-07-05
 
 ### Features

baseapp/abci.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 	"strings"
 	"syscall"
+	"time"
 
 	"github.com/gogo/protobuf/proto"
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -394,6 +395,10 @@ 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)
+	defer telemetry.MeasureSince(time.Now(), 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) {