Admin port with Dropwizard metrics not working

Question

I'm following the DropWizard "Getting Started" tutorial and while I got everything else working the 8081 admin port is blank and clicking on any of the hyperlinks to the metrics resource, threads resource, and health check resource is giving me a 101 error. Can't figure out why I followed it pretty much verbatim. Here's my POM if that helps:

    <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>DropWizard</groupId>
    <artifactId>DropWizard</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>com.yammer.dropwizard</groupId>
            <artifactId>dropwizard-core</artifactId>
            <version>0.6.2</version>
        </dependency>
        <dependency>
            <groupId>com.codahale.metrics</groupId>
            <artifactId>metrics-core</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>com.codahale.metrics</groupId>
            <artifactId>metrics-servlets</artifactId>
            <version>3.0.0</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>1.6</version>
                <configuration>
                    <createDependencyReducedPom>true</createDependencyReducedPom>
                    <filters>
                        <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                                <exclude>META-INF/*.SF</exclude>
                                <exclude>META-INF/*.DSA</exclude>
                                <exclude>META-INF/*.RSA</exclude>
                            </excludes>
                        </filter>
                    </filters>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
                                <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>com.example.helloworld.HelloWorldService</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <archive>
                        <manifest>
                            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Answer 1

Figured it out, there are a couple of things to note:

1) If you specify the dropwizard dependency you do not need to specify the metrics dependencies.

2) The 8081 port, for whatever reason, was not cooperating. When I changed the admin port to 9091 everything worked as expected. If you want to change the ports then specify the following in your admin file:

http:
    port: 9090
    adminPort: 9091

I assume you can use whatever ports you like, these happened to work when I used them. When specifying the ports there must be a tab in between http and the information that comes afterwards. Hopefully this helps others avoid the hair-pulling frustration I encountered

Answer 2

The Dropwizard admin interface (as of 0.6.2) is only compatible with Metrics 2.*. Dropwizard 0.7.0 will work with Metrics 3 once it's released.