Prometheus not exporting Kafka Consumer data upon upgrade from Spring Boot 2.1.6 to 2.2.2

Question

We upgraded Spring Boot version from 2.1.6 to 2.2.2. Some of the properties being seen in the Prometheus endpoint in 2.1.6 is not visible in 2.2.2.

• kafka_consumer_records_consumed_total_records_total
• kafka_consumer_records_lag_records
• kafka_consumer_fetch_latency_max_seconds
• kafka_consumer_bytes_consumed_total_bytes_total

However, this data is being registered in MBeans.

Example for kafka_consumer_records_consumed_total_records_total

Am I missing some configurations? How can I export this data available in MBeans to the actuator endpoint ("/prometheus") ?

Update: Prometheus version we are using in both versions is the same.

    1.3.1

POM.xml (Before the change)

<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.example</groupId>
<artifactId>actuator-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>actuator-demo</name>
<description>Spring Boot Actuator Demo Project</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.6.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

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

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

    <!-- Micrometer Prometheus registry  -->
    <dependency>
        <groupId>io.micrometer</groupId>
        <artifactId>micrometer-registry-prometheus</artifactId>
    </dependency>

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

    <dependency>
        <groupId>org.springframework.kafka</groupId>
        <artifactId>spring-kafka</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.kafka</groupId>
        <artifactId>spring-kafka-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <artifactId>jackson-databind</artifactId>
                <groupId>com.fasterxml.jackson.core</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-contract-wiremock</artifactId>
    </dependency>
    <dependency>
        <groupId>io.projectreactor.kafka</groupId>
        <artifactId>reactor-kafka</artifactId>
    </dependency>


</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

POM.xml (After the change -- Only Spring Boot is upgraded)

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>actuator-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>actuator-demo</name>
    <description>Spring Boot Actuator Demo Project</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

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

        <!-- Micrometer Prometheus registry  -->
        <dependency>
            <groupId>io.micrometer</groupId>
            <artifactId>micrometer-registry-prometheus</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <artifactId>jackson-databind</artifactId>
                    <groupId>com.fasterxml.jackson.core</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-contract-wiremock</artifactId>
        </dependency>
        <dependency>
            <groupId>io.projectreactor.kafka</groupId>
            <artifactId>reactor-kafka</artifactId>
        </dependency>


    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Answer 1

Kafka metrics are using JMX and JMX is disabled by default as of Spring Boot 2.2. You need to enable JMX for Kafka Metrics to work, i.e. spring.jmx.enabled=true in your configuration.