# OpenTelemetry ### Overview OpenTelemetry is a collection of tools, APIs, and SDKs. Use it to instrument, generate, collect, and export telemetry data (metrics, logs, and traces) to help analyze software’s performance and behavior. {% hint style="danger" %} We recommend using the OpenTelemetry HTTP exporter to send logs, metrics and traces to Apica Ascent. {% endhint %} ### OTLP Http exporter ```yaml otlphttp: endpoint: https:// encoding: json compression: gzip headers: Authorization: "Bearer " tls: insecure: false insecure_skip_verify: true ``` {% hint style="info" %} Encoding type must be JSON for logs and traces. We currently only support protobuf encoding for metrics. When using metrics\_endpoint with proto encoding, remove the compression setting. {% endhint %} {% hint style="warning" %} Apica telemetry pipeline only supports data for metrics in OTLP format. Sending data to the prometheus remote write endpoint will not allow manipulation of metrics via the telemetry pipeline {% endhint %} ### Prometheus remote write exporter Prometheus Remote Write Exporter can be used to send OpenTelemetry metrics to Prometheus [remote write compatible backends](https://prometheus.io/docs/operating/integrations/) Apica Ascent implements a Prometheus remote write backend so metric data from open telemetry collectors can be sent to Apica Ascent with a simple configuration as described below. Enable the *prometheusremorewrite* exporter in your open telemetry configuration yaml ```yaml exporters: prometheusremotewrite: ``` Specify the Apica Ascent cluster endpoint to send the remote write data. Apica Ascent implements automatic retention tiering to object storage for all your opentelemetry metrics data giving you infinite retention and scale with zero storage overheads as your metrics needs grow. ``` endpoint: "https:///v1/receive/prometheus" ``` The endpoint is authenticated and requires bearer token to be sent as part of the request ```yaml headers: Authorization: "Bearer /v1/receive/prometheus" headers: Authorization: "Bearer " wal: # Enabling the Write-Ahead-Log for the exporter. directory: ./prom_rw # The directory to store the WAL in buffer_size: 100 # Optional count of elements to be read from the WAL before truncating; default of 300 truncate_frequency: 45s # Optional frequency for how often the WAL should be truncated. It is a time.ParseDuration; default of 1m tls: ca_file: cert_file: key_file: external_labels: #labels to identify the metric label1: value1 receivers: otlp: protocols: grpc: http: processors: batch: service: pipelines: metrics: receivers: [otlp] processors: [batch] exporters: [prometheusremotewrite] ``` ### Scraping Prometheus Metrics In the OpenTelemetry config file, you can include a scrape section to scrape data from Prometheus endpoints. You can subsequently push that to a remote Prometheus compatible write endpoint using instructions from the section above. ``` receivers: prometheus: config: scrape_configs: - job_name: 'otel-collector' scrape_interval: 10s static_configs: - targets: ['0.0.0.0:8888'] service: pipelines: metrics: receivers: [prometheus] ``` ### Language Integrations #### Java If you are writing a Java-based application and want to enable OpenTelemetry for instrumenting your application logs, traces, and metrics, you can use the OpenTelemetry Java agent Jar file to attach to your existing Java applications. The Jar file can be found here - {% hint style="danger" %} the Prometheus metrics options create a pull metric instance that should be scraped by an external Prometheus compatible instance {% endhint %}

JAVA_OPTS	Value	Notes
otel.service_name	<User defined>	Give a service name to group your OpenTelemetry data traces under this service name
otel.traces.exporter	otlp
otel.exporter.otlp.endpoint	https://<Apica Ascent ENDPOINT>	Apica Ascent OpenTelemetry endpoint
javaagent	<PATH TO JAR>/opentelemetry-javaagent.jar	OpenTelemetry agent Jar file
otel.metrics.exporter	prometheus
otel.exporter.prometheus.port		Default port is 9464
otel.exporter.prometheus.host		Default is 0.0.0.0

$> java -javaagent:opentelemetry-javaagent.jar -Dotel.exporter.otlp.certificate=./ca.crt -Dotel.traces.exporter=otlp -Dotel.exporter.otlp.endpoint=https://$APICA_ASCENT_SERVER -Dotel.metrics.exporter=none -Dotel.service-name=java-petclinic-sample-app -Dotel.exporter.logging.prefix -jar -Djava.util.logging.config.file=logging.properties target/spring-petclinic-2.7.0-SNAPSHOT.jar --server.port=8080

{% hint style="info" %} When using TLS please ensure you have the CA cert of the Apica Ascent environment installed in the JVM Cert store. Instructions can be found here - {% endhint %} ![](https://2948796384-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LmzGprckLqwd5v6bs6m%2Fuploads%2FWqkuNarjUcxnlDiOuXo1%2FScreenshot%202024-08-19%20at%203.25.53%E2%80%AFAM.png?alt=media\&token=cbf04d4f-52ab-47a0-a18b-b32ed9944169) ### Example Petclinic app with open telemetry integration You can use our freely available petclinc java application for opentelmetry integration testing. Just launch our free container as below and point it to the Apica service IP/DNS {% code overflow="wrap" %} ``` docker run -d -p 8080:8080 -e BACKEND_HOST={apica_host}.apica.io -e BACKEND_SCHEME=https -e API_TOKEN="{Apica_Ingest_Token}" apica/petclinic-open-telemetry:v1.0 ``` {% endcode %} [^1]: TLS Enabled, Use http if TLS is not enabled.