2024-03-27 15:04:43 +00:00
---
weight: 5
title: How to use OpenTelemetry metrics with VictoriaMetrics
menu:
docs:
parent: "guides"
weight: 5
---
VictoriaMetrics supports metrics ingestion with [OpenTelemetry metrics format ](https://opentelemetry.io/docs/specs/otel/metrics/ ).
This guide covers data ingestion via [opentelemetry-collector ](https://opentelemetry.io/docs/collector/ ) and direct metrics push from application.
## Pre-Requirements
* [kubernetes cluster ](https://kubernetes.io/docs/tasks/tools/#kind )
* [kubectl ](https://kubernetes.io/docs/tasks/tools/#kubectl )
* [helm ](https://helm.sh/docs/intro/install/ )
### Install VictoriaMetrics single-server via helm chart
Install single-server version:
```sh
helm repo add vm https://victoriametrics.github.io/helm-charts/
helm repo update
helm install victoria-metrics vm/victoria-metrics-single
```
Verify it's up and running:
```sh
kubectl get pods
# victoria-metrics-victoria-metrics-single-server-0 1/1 Running 0 3m1s
```
Helm chart provides the following urls for reading and writing data:
```text
Write url inside the kubernetes cluster:
http://victoria-metrics-victoria-metrics-single-server.default.svc.cluster.local:8428
Read Data:
The following url can be used as the datasource url in Grafana:
http://victoria-metrics-victoria-metrics-single-server.default.svc.cluster.local:8428
```
## Using opentelemetry-collector with VictoriaMetrics
2024-07-24 08:00:31 +00:00
2024-03-27 15:04:43 +00:00
### Deploy opentelemetry-collector and configure metrics forwarding
```sh
helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
helm repo update
# add values
cat < < EOF > values.yaml
2024-06-26 09:16:21 +00:00
mode: deployment
image:
repository: "otel/opentelemetry-collector-contrib"
2024-03-27 15:04:43 +00:00
presets:
clusterMetrics:
enabled: true
config:
2024-06-26 09:16:21 +00:00
receivers:
otlp:
protocols:
grpc:
endpoint: 0.0.0.0:4317
http:
endpoint: 0.0.0.0:4318
2024-03-27 15:04:43 +00:00
exporters:
2024-06-26 09:16:21 +00:00
otlphttp/victoriametrics:
compression: gzip
encoding: proto
endpoint: http://victoria-metrics-victoria-metrics-single-server.default.svc.cluster.local:8428/opentelemetry
tls:
insecure: true
2024-03-27 15:04:43 +00:00
service:
2024-06-26 09:16:21 +00:00
pipelines:
metrics:
receivers: [otlp]
processors: []
exporters: [otlphttp/victoriametrics]
2024-03-27 15:04:43 +00:00
EOF
# install helm chart
2024-06-26 09:16:21 +00:00
helm upgrade -i otl-collector open-telemetry/opentelemetry-collector -f values.yaml
2024-03-27 15:04:43 +00:00
# check if pod is healthy
kubectl get pod
2024-06-03 08:04:13 +00:00
NAME READY STATUS RESTARTS AGE
otl-collector-opentelemetry-collector-7467bbb559-2pq2n 1/1 Running 0 23m
2024-03-27 15:04:43 +00:00
# forward port to local machine to verify metrics are ingested
2024-06-26 09:16:21 +00:00
kubectl port-forward service/victoria-metrics-victoria-metrics-single-server 8428
2024-03-27 15:04:43 +00:00
# check metric `k8s_container_ready` via browser http://localhost:8428/vmui/#/?g0.expr=k8s_container_ready
2024-06-26 09:16:21 +00:00
# forward port to local machine to setup opentelemetry-collector locally
kubectl port-forward otl-collector-opentelemetry-collector 4318
2024-03-27 15:04:43 +00:00
```
The full version of possible configuration options could be found in [OpenTelemetry docs ](https://opentelemetry.io/docs/collector/configuration/ ).
2024-06-26 09:16:21 +00:00
## Sending to VictoriaMetrics via OpenTelemetry
Metrics could be sent to VictoriaMetrics via OpenTelemetry instrumentation libraries. You can use any compatible OpenTelemetry instrumentation [clients ](https://opentelemetry.io/docs/languages/ ).
In our example, we'll create a WEB server in [Golang ](https://go.dev/ ) and instrument it with metrics.
### Building the Go application instrumented with metrics
Copy the go file from [here ](/guides/getting-started-with-opentelemetry-app.go-collector.example ). This will give you a basic implementation of a dice roll WEB server with the urls for opentelemetry-collector pointing to localhost:4318.
In the same directory run the following command to create the `go.mod` file:
```sh
go mod init vm/otel
```
For demo purposes, we'll add the following dependencies to `go.mod` file:
```go
require (
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.52.0
go.opentelemetry.io/otel v1.27.0
go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.27.0
go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.27.0
go.opentelemetry.io/otel/metric v1.27.0
go.opentelemetry.io/otel/sdk v1.27.0
go.opentelemetry.io/otel/sdk/metric v1.27.0
)
require (
github.com/cenkalti/backoff/v4 v4.3.0 // indirect
github.com/felixge/httpsnoop v1.0.4 // indirect
github.com/go-logr/logr v1.4.1 // indirectdice.rolls
github.com/go-logr/stdr v1.2.2 // indirect
github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect
go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.27.0 // indirect
go.opentelemetry.io/otel/trace v1.27.0 // indirect
go.opentelemetry.io/proto/otlp v1.2.0 // indirect
golang.org/x/net v0.25.0 // indirect
golang.org/x/sys v0.20.0 // indirect
golang.org/x/text v0.15.0 // indirect
google.golang.org/genproto/googleapis/api v0.0.0-20240520151616-dc85e6b867a5 // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20240515191416-fc5f0ca64291 // indirect
google.golang.org/grpc v1.64.0 // indirect
google.golang.org/protobuf v1.34.1 // indirect
)
```
Once you have these in your `go.mod` file, you can run the following command to download the dependencies:
```sh
go mod tidy
```
Now you can run the application:
```sh
go run .
```
### Test metrics ingestion
By default, the application will be available at `localhost:8080` . You can start sending requests to /rolldice endpoint to generate metrics. The following command will send 20 requests to the /rolldice endpoint:
```sh
for i in `seq 1 20` ; do curl http://localhost:8080/rolldice; done
```
After a few seconds you should start to see metrics sent over to the vmui interface by visiting `http://localhost:8428/vmui/#/?g0.expr=dice.rolls` in your browser or by querying the metric `dice.rolls` in the vmui interface.
2024-07-24 08:00:31 +00:00
2024-03-27 15:04:43 +00:00
## Direct metrics push
Metrics could be ingested into VictoriaMetrics directly with HTTP requests. You can use any compatible OpenTelemetry
instrumentation [clients ](https://opentelemetry.io/docs/languages/ ).
In our example, we'll create a WEB server in [Golang ](https://go.dev/ ) and instrument it with metrics.
2024-07-24 08:00:31 +00:00
2024-03-27 15:04:43 +00:00
### Building the Go application instrumented with metrics
2024-03-28 07:58:27 +00:00
See the full source code of the example [here ](/guides/getting-started-with-opentelemetry-app.go.example ).
2024-03-27 15:04:43 +00:00
The list of OpenTelemetry dependencies for `go.mod` is the following:
```go
go 1.20
require (
go.opentelemetry.io/otel v1.7.0
go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.30.0
go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v0.30.0
go.opentelemetry.io/otel/metric v0.30.0
go.opentelemetry.io/otel/sdk v1.7.0
go.opentelemetry.io/otel/sdk/metric v0.30.0
)
```
Let's create a new file `main.go` with basic implementation of the WEB server:
```go
package main
func main() {
mux := http.NewServeMux()
mux.HandleFunc("/api/fast", func(writer http.ResponseWriter, request *http.Request) {
writer.WriteHeader(http.StatusOK)
writer.Write([]byte(`fast ok`))
})
mux.HandleFunc("/api/slow", func(writer http.ResponseWriter, request *http.Request) {
time.Sleep(time.Second * 2)
writer.WriteHeader(http.StatusOK)
writer.Write([]byte(`slow ok`))
})
mw, err := newMetricsMiddleware(mux)
if err != nil {
panic(fmt.Sprintf("cannot build metricMiddleWare: %q", err))
}
go func() {
http.ListenAndServe("localhost:8081", mw)
}()
}
```
In the code above, we used `newMetricsMiddleware` function to create a `handler` for our server.
Let's define it below:
```go
type metricMiddleWare struct {
h http.Handler
requestsCount syncint64.Counter
requestsLatency syncfloat64.Histogram
activeRequests int64
}
func newMetricsMiddleware(h http.Handler) (*metricMiddleWare, error) {
mw := & metricMiddleWare{h: h}
mc, err := newMetricsController(ctx)
if err != nil {
return nil, fmt.Errorf("cannot build metrics collector: %w", err)
}
global.SetMeterProvider(mc)
prov := mc.Meter("")
mw.requestsLatency, err = prov.SyncFloat64().Histogram("http_request_latency_seconds")
if err != nil {
return nil, fmt.Errorf("cannot create histogram: %w", err)
}
mw.requestsCount, err = prov.SyncInt64().Counter("http_requests_total")
if err != nil {
return nil, fmt.Errorf("cannot create syncInt64 counter: %w", err)
}
ar, err := prov.AsyncInt64().Gauge("http_active_requests")
if err != nil {
return nil, fmt.Errorf("cannot create AsyncInt64 gauge: %w", err)
}
if err := prov.RegisterCallback([]instrument.Asynchronous{ar}, func(ctx context.Context) {
ar.Observe(ctx, atomic.LoadInt64(& mw.activeRequests))
}); err != nil {
return nil, fmt.Errorf("cannot Register int64 gauge: %w", err)
}
return mw, nil
}
```
The new type `metricMiddleWare` is instrumented with 3 [metrics ](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#timeseries-model )
initialized in `newMetricsMiddleware` method:
* counter `http_requests_total`
* histogram `http_request_latency_seconds`
* gauge `http_active_requests`
Let's implement http.Handler interface for `metricMiddleWare` by adding `ServeHTTP` method:
```go
func (m *metricMiddleWare) ServeHTTP(w http.ResponseWriter, r *http.Request) {
t := time.Now()
path := r.URL.Path
m.requestsCount.Add(nil, 1, attribute.String("path", path))
atomic.AddInt64(& m.activeRequests, 1)
defer func() {
atomic.AddInt64(& m.activeRequests, -1)
m.requestsLatency.Record(nil, time.Since(t).Seconds(), attribute.String("path", path))
}()
m.h.ServeHTTP(w, r)
}
```
In method above, our middleware processes received HTTP requests and updates metrics with each new request.
But for these metrics to be shipped we need to add a new method `newMetricsController` to organize metrics collection:
```go
func newMetricsController(ctx context.Context) (*controller.Controller, error) {
options := []otlpmetrichttp.Option{
otlpmetrichttp.WithEndpoint("< VictoriaMetrics endpoint - host:port > "),
otlpmetrichttp.WithURLPath("/opentelemetry/api/v1/push"),
}
metricExporter, err := otlpmetrichttp.New(ctx, options...)
if err != nil {
return nil, fmt.Errorf("cannot create otlphttp exporter: %w", err)
}
resourceConfig, err := resource.New(ctx, resource.WithAttributes(attribute.String("job", "otlp"), attribute.String("instance", "localhost")))
if err != nil {
return nil, fmt.Errorf("cannot create meter resource: %w", err)
}
meterController := controller.New(
processor.NewFactory(
selector.NewWithHistogramDistribution(
histogram.WithExplicitBoundaries([]float64{0.01, 0.05, 0.1, 0.5, 0.9, 1.0, 5.0, 10.0, 100.0}),
),
aggregation.CumulativeTemporalitySelector(),
processor.WithMemory(true),
),
controller.WithExporter(metricExporter),
controller.WithCollectPeriod(time.Second * 10),
controller.WithResource(resourceConfig),
)
if err := meterController.Start(ctx); err != nil {
return nil, fmt.Errorf("cannot start meter controller: %w", err)
}
return meterController, nil
}
```
This controller will collect and push collected metrics to VictoriaMetrics address with interval of `10s` .
2024-03-28 07:58:27 +00:00
See the full source code of the example [here ](/guides/getting-started-with-opentelemetry-app.go.example ).
2024-03-27 15:04:43 +00:00
### Test metrics ingestion
2024-06-14 12:01:44 +00:00
In order to push metrics of our WEB server to VictoriaMetrics it is necessary to ensure that VictoriaMetrics ingestion
endpoint is available locally.
2024-03-27 15:04:43 +00:00
In previous steps we already deployed a single-server VictoriaMetrics, so let's make it available locally:
```sh
# port-forward victoriametrics to ingest metrics
kubectl port-forward victoria-metrics-victoria-metrics-single-server-0 8428
```
Now let's run our WEB server and call its APIs:
```sh
# build and run the app
go run main.go
2024/03/25 19:27:41 Starting web server...
2024/03/25 19:27:41 web server started at localhost:8081.
# execute few queries with curl
curl http://localhost:8081/api/fast
curl http://localhost:8081/api/slow
```
Open [vmui ](https://docs.victoriametrics.com/#vmui ) and query `http_requests_total` or `http_active_requests`
with [metricsql ](https://docs.victoriametrics.com/metricsql/ ).
2024-07-24 08:00:31 +00:00
2024-03-27 15:04:43 +00:00
## Limitations
* VictoriaMetrics doesn't support experimental JSON encoding [format ](https://github.com/open-telemetry/opentelemetry-proto/blob/main/examples/metrics.json ).
* VictoriaMetrics supports only `AggregationTemporalityCumulative` type for [histogram ](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#histogram ) and [summary ](https://opentelemetry.io/docs/specs/otel/metrics/data-model/#summary-legacy )
