Spring Boot 3 + OpenTelemetry

application.properties

# For OTLP - OTLP Prometheus endpoint, OTLP requires pushing
management.otlp.metrics.export.url=http://localhost:9090/api/v1/otlp/v1/metrics
# only for demo purposes
management.otlp.metrics.export.step=2s
# All traces should be sent to latency analysis tool
management.tracing.sampling.probability=1.0
# OTLP endpoint - OTLP Tempo endpoint
management.zipkin.tracing.endpoint=http://localhost:4318/v1/traces
management.zipkin.tracing.encoding=PROTO3

# For Exemplars to work we need histogram buckets - TODO: Micrometer OTLP doesn't yet support exemplars
management.metrics.distribution.percentiles-histogram.http.server.requests=true

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml" />
    <springProperty scope="context" name="appName" source="spring.application.name"/>

    <appender name="LOKI" class="com.github.loki4j.logback.Loki4jAppender">
        <http>
            <url>http://localhost:3100/loki/api/v1/push</url>
        </http>
        <format>
            <label>
                <pattern>app=${appName},host=${HOSTNAME},level=%level</pattern>
            </label>
            <message>
                <pattern>${FILE_LOG_PATTERN}</pattern>
            </message>
            <sortByTime>true</sortByTime>
        </format>
    </appender>

    <root level="INFO">
        <appender-ref ref="LOKI"/>
    </root>
</configuration>

pom.xml

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!-- Prerequisite for observability -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>

		<!-- For Observation AOP -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
		</dependency>
		<!-- For Metrics -->
		<!-- For OTLP -->
		<dependency>
			<groupId>io.micrometer</groupId>
			<artifactId>micrometer-registry-otlp</artifactId>
		</dependency>

		<!-- Brave version -->
		<!-- For Tracing -->
		<dependency>
			<groupId>io.micrometer</groupId>
			<artifactId>micrometer-tracing-bridge-brave</artifactId>
		</dependency>
		<!-- For Latency Visualization -->
		<dependency>
			<groupId>io.zipkin.contrib.otel</groupId>
			<artifactId>encoder-brave</artifactId>
			<version>0.1.0</version>
		</dependency>

		<!-- For pushing logs out -->
		<dependency>
			<groupId>com.github.loki4j</groupId>
			<artifactId>loki-logback-appender</artifactId>
			<version>1.5.2</version>
			<scope>runtime</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>