Collecting Application Logs Using OTEL Java Agent

You can directly send your application logs to SigNoz using Java Agent provided by OpenTelemetry. In this doc we will run a sample java application with the OpenTelemetry Java agent to send logs to SigNoz.

For collecting logs we will have to download the java agent from here.

To sends logs from a Java application you will have to add the agent and add the environment variables for the agent.

For Sending Logs To SigNoz Cloud

OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="https://ingest.{region}.signoz.cloud:443" OTEL_EXPORTER_OTLP_HEADERS=signoz-access-token=<SIGNOZ_INGESTION_KEY> OTEL_RESOURCE_ATTRIBUTES=service.name=<app_name> java -javaagent:/path/opentelemetry-javaagent.jar -jar  <myapp>.jar

You will have to add <SIGNOZ_INGESTION_KEY> and depending on the choice of your region for SigNoz cloud, the otlp endpoint will vary according to this table.

Region	Endpoint
US	ingest.us.signoz.cloud:443
IN	ingest.in.signoz.cloud:443
EU	ingest.eu.signoz.cloud:443

For Sending Logs To SigNoz Hosted Locally

OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="http://<IP of SigNoz Backend>:4317" OTEL_RESOURCE_ATTRIBUTES=service.name=<app_name> java -javaagent:/path/opentelemetry-javaagent.jar -jar  <myapp>.jar

Settings for Appender instrumentation based on the logging library

You can use appender settings by passing it as an argument in the -D<property>=<value> format.

ex:- -Dotel.instrumentation.logback-appender.experimental-log-attributes=true

Logback

System property	Type	Default Value	Description
otel.instrumentation.logback-appender.experimental-log-attributes	Boolean	false	Enable the capture of experimental log attributes thread.name and thread.id.
otel.instrumentation.logback-appender.experimental.capture-code-attributes	Boolean	false	Enable the capture of [source code attributes]. Note that capturing source code attributes at logging sites might add a performance overhead.
otel.instrumentation.logback-appender.experimental.capture-marker-attribute	Boolean	false	Enable the capture of Logback markers as attributes.
otel.instrumentation.logback-appender.experimental.capture-key-value-pair-attributes	Boolean	false	Enable the capture of Logback key value pairs as attributes.
otel.instrumentation.logback-appender.experimental.capture-logger-context-attributes	Boolean	false	Enable the capture of Logback logger context properties as attributes.
otel.instrumentation.logback-appender.experimental.capture-mdc-attributes	String	NA	Comma separated list of MDC attributes to capture. Use the wildcard character * to capture all attributes.

Log4j

System property	Type	Default	Description
otel.instrumentation.log4j-appender.experimental-log-attributes	Boolean	false	Enable the capture of experimental log attributes thread.name and thread.id.
otel.instrumentation.log4j-appender.experimental.capture-map-message-attributes	Boolean	false	Enable the capture of MapMessage attributes.
otel.instrumentation.log4j-appender.experimental.capture-marker-attribute	Boolean	false	Enable the capture of Log4j markers as attributes.
otel.instrumentation.log4j-appender.experimental.capture-mdc-attributes	String		Comma separated list of context data attributes to capture. Use the wildcard character * to capture all attributes.

In the below example we will configure a java application to send logs to SigNoz.

[Example] How to Collect Application Logs Using OTEL Java Agent?

• Clone this repository

• Build the application using ./mvnw package

• Now run the application

  For SigNoz Cloud

  OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="https://ingest.{region}.signoz.cloud:443" OTEL_EXPORTER_OTLP_HEADERS=signoz-access-token=<SIGNOZ_INGESTION_KEY> OTEL_RESOURCE_ATTRIBUTES=service.name=myapp java -javaagent:/path/opentelemetry-javaagent.jar -jar target/*.jar

  You will have to replace the value of {region} according to region of your cloud account and also add <SIGNOZ_INGESTION_KEY>

  For SigNoz Hosted Locally

  OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="http://<host>:4317" OTEL_RESOURCE_ATTRIBUTES=service.name=myapp java -javaagent:/path/opentelemetry-javaagent.jar -jar target/*.jar

  You will have to replace your the value of host as 0.0.0.0 if SigNoz is running in the same host, for other configurations please check the troubleshooting guide.

• Visit http://localhost:8090 to access the application.

• Once you use the application logs will be visible on SigNoz UI.

• If you want to enable settings here is how you do it. Let's say we want to enable -Dotel.instrumentation.logback-appender.experimental-log-attributes=true

  For SigNoz Cloud

  OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="https://ingest.{region}.signoz.cloud:443" OTEL_EXPORTER_OTLP_HEADERS=signoz-access-token=<SIGNOZ_INGESTION_KEY> OTEL_RESOURCE_ATTRIBUTES=service.name=myapp java -javaagent:/path/opentelemetry-javaagent.jar -Dotel.instrumentation.logback-appender.experimental-log-attributes=true -jar target/*.jar

  You will have to replace the value of {region} according to the region of your cloud account and also replace <SIGNOZ_INGESTION_KEY> with your SigNoz Cloud Ingestion key.

  For SigNoz Hosted Locally

  OTEL_LOGS_EXPORTER=otlp OTEL_EXPORTER_OTLP_ENDPOINT="http://<host>:4317" OTEL_RESOURCE_ATTRIBUTES=service.name=myapp java -javaagent:/path/opentelemetry-javaagent.jar -Dotel.instrumentation.logback-appender.experimental-log-attributes=true -jar target/*.jar