Enhancing Boot Application with Metrics

Set up the Actuator

Spring Boot includes a number of additional features to help you monitor and manage your application when it’s pushed to production. These features are added by adding spring-boot-starter-actuator to the classpath. During our initial project setup with start.spring.io we’ve already included that.

Verify the Spring Boot Actuator dependency the following file: /cloud-native-spring/pom.xml. You should see the following dependency in the list:
```
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
```
By default, Spring Boot will only expose "health" and "info" endpoints (which is a good thing!). As part of our demo app, we will choose to expose all available actuator endpoints. . Add the following properties to cloud-native-spring/src/main/resources/application.properties. You may have to create the file first.
```
management.endpoints.web.exposure.include=* # add this section
```
Run the updated application
```
$ mvn clean spring-boot:run
```
Try out the following endpoints. The output is omitted here because it can be quite large:

http://localhost:8080/actuator/health

Displays Application and Datasource health information. This can be customized based on application functionality, which we’ll do later.

http://localhost:8080/actuator/beans

Displays a complete list of all the Spring beans in your application.

http://localhost:8080/actuator/httptrace

Displays HTTP trace information (by default, the last 100 HTTP request-response exchanges).

http://localhost:8080/actuator/configprops

Displays a collated list of all @ConfigurationProperties.

http://localhost:8080/actuator/env

Exposes properties from Spring’s ConfigurableEnvironment.

http://localhost:8080/actuator/mappings

Displays all URI request mappings and the controller methods to which they are mapped.

http://localhost:8080/actuator/threaddump

Performs a thread dump.

http://localhost:8080/actuator/conditions

Shows the conditions that were evaluated on configuration and auto-configuration classes and the reasons why they did or did not match.

More details on actuator endpoints here
Stop the cloud-native-spring application.

Include Version Control Info

Spring Boot provides an endpoint (http://localhost:8080/actuator/info) that allows the exposure of arbitrary metadata. By default, it is empty.

One thing that actuator does well is expose information about the specific build and version control coordinates for a given deployment.

Edit the following file: /cloud-native-spring/pom.xml. Add the git-commit-id-plugin to your Maven build. You must edit the file and add the plugin code below into the existing <plugins> XML structure, which should already have one plugin defined. The git-commit-id-plugin adds Git branch and commit coordinates to the /info endpoint:
```
<plugin>
	<groupId>pl.project13.maven</groupId>
	<artifactId>git-commit-id-plugin</artifactId>
	<configuration>
		<dotGitDirectory>../../../.git</dotGitDirectory>
	</configuration>
</plugin>
```
NOTE The path ../../../.git refers to the .git directory at the root of the lab materials repo.

Completed:

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>io.pivotal</groupId>
    <artifactId>cloud-native-spring</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>cloud-native-spring</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <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-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-rest</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-rest-hal-browser</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>pl.project13.maven</groupId>
                <artifactId>git-commit-id-plugin</artifactId>
                <configuration>
                    <dotGitDirectory>../../../.git</dotGitDirectory>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Run the cloud-native-spring application:

$ mvn clean spring-boot:run

Browse to http://localhost:8080/actuator/info. Git commit information is now included

{
  "git": {
    "commit": {
      "time": "2019-02-22T17:55:02Z",
      "id": "edcced7"
    },
    "branch": "master"
  }
}

Stop the cloud-native-spring application

What Just Happened?

By including the git-commit-id-plugin, details about git commit information will be included in the /actuator/info endpoint. Git information is captured in a git.properties file that is generated with the build. Review the following file: /cloud-native-spring/target/classes/git.properties

Include Build Info

Add the following properties to cloud-native-spring/src/main/resources/application.properties. You may have to create the file first.
```
management.info.git.mode=full # add this section
```
This will expose full git info on the /actuator/info endpoint.
Build and run the cloud-native-spring application:
```
$ mvn clean spring-boot:run
```

Browse to http://localhost:8080/actuator/info. Build information is now included.

{
  "git": {
    "build": {
      "host": "Sharads-MacBook-Pro.local",
      "version": "0.0.1-SNAPSHOT",
      "time": "2019-02-22T18:14:57Z",
      "user": {
        "name": "sharadg",
        "email": "91043+sharadg@users.noreply.github.com"
      }
    },
    "branch": "master",
    "commit": {
      "message": {
        "short": "Updated content for Lab02",
        "full": "Updated content for Lab02"
      },
      "id": {
        "describe": "edcced7-dirty",
        "abbrev": "edcced7",
        "describe-short": "edcced7-dirty",
        "full": "edcced703bddf4832e371496afbfd0af7827c2f8"
      },
      "time": "2019-02-22T17:55:02Z",
      "user": {
        "email": "91043+sharadg@users.noreply.github.com",
        "name": "sharadg"
      }
    },
    "closest": {
      "tag": {
        "name": "",
        "commit": {
          "count": ""
        }
      }
    },
    "dirty": "true",
    "remote": {
      "origin": {
        "url": "https://github.com/sharadg/Cloud-Native-Java-Workshop"
      }
    },
    "tags": "",
    "total": {
      "commit": {
        "count": "173"
      }
    }
  }
}

Stop the cloud-native-spring application.

What Just Happened?

We have mapped git commit properties from the pom.xml into the /actuator/info endpoint.

Read more about exposing data in the /actuator/info endpoint here

Health Indicators

Spring Boot provides an endpoint http://localhost:8080/actuator/health that exposes various health indicators that describe the health of the given application.

Normally, when Spring Security is not enabled, the /actuator/health endpoint will only expose an UP or DOWN value.

{
  "status": "UP"
}

To simplify working with the endpoint for this lab, we will turn off additional security for the health endpoint. Add the following to /cloud-native-spring/src/main/resources/application.properties:
```
management.endpoint.health.show-details=always
```
Build and run the cloud-native-spring application:
```
$ mvn clean spring-boot:run
```

Browse to http://localhost:8080/actuator/health. Out of the box is a DiskSpaceHealthIndicator that monitors health in terms of available disk space.

Would your Ops team like to know if the app is close to running out of disk space? DiskSpaceHealthIndicator can be customized via DiskSpaceHealthIndicatorProperties.

{
  "status": "UP",
  "details": {
    "db": {
      "status": "UP",
      "details": {
        "database": "H2",
        "hello": 1
      }
    },
    "diskSpace": {
      "status": "UP",
      "details": {
        "total": 499963170816,
        "free": 87024320512,
        "threshold": 10485760
      }
    }
  }
}

Stop the cloud-native-spring application.

Create the class io.pivotal.cloudnativespring.FlappingHealthIndicator (/cloud-native-spring/src/main/java/io/pivotal/cloudnativespring/FlappingHealthIndicator.java) and into it paste the following code:

package io.pivotal.cloudnativespring;

import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;

import java.util.Random;

@Component
public class FlappingHealthIndicator implements HealthIndicator {
    private Random random = new Random(System.currentTimeMillis());

    @Override
    public Health health() {
        int result = random.nextInt(100);
        if(result < 50) {
            return Health.down()
                         .withDetail("flapper", "failure")
                         .withDetail("random", result)
                         .build();
        } else {
            return Health.up()
                         .withDetail("flapper", "ok")
                         .withDetail("random", result)
                         .build();
        }
    }
}

This demo health indicator will randomize the health check.

Build and run the cloud-native-spring application:
```
$ mvn clean spring-boot:run
```

Browse to http://localhost:8080/actuator/health and verify that the output is similar to the following (and changes randomly!).

{
  "status": "UP",
  "details": {
    "flapping": {
      "status": "UP",
      "details": {
        "flapper": "ok",
        "random": 76
      }
    },
    "db": {
      "status": "UP",
      "details": {
        "database": "H2",
        "hello": 1
      }
    },
    "diskSpace": {
      "status": "UP",
      "details": {
        "total": 499963170816,
        "free": 86771916800,
        "threshold": 10485760
      }
    }
  }
}

{
  "status": "DOWN",
  "details": {
    "flapping": {
      "status": "DOWN",
      "details": {
        "flapper": "failure",
        "random": 25
      }
    },
    "db": {
      "status": "UP",
      "details": {
        "database": "H2",
        "hello": 1
      }
    },
    "diskSpace": {
      "status": "UP",
      "details": {
        "total": 499963170816,
        "free": 86769766400,
        "threshold": 10485760
      }
    }
  }
}

Metrics

Spring Boot provides an endpoint http://localhost:8080/actuator/metrics that exposes several automatically collected metrics for your application. It also allows for the creation of custom metrics.

Browse to http://localhost:8080/actuator/metrics. Review the metrics exposed.

{
  "names": [
    "jvm.memory.max",
    "jvm.threads.states",
    "jdbc.connections.active",
    "process.files.max",
    "jvm.gc.memory.promoted",
    "http.server.requests",
    "system.load.average.1m",
    "jvm.memory.used",
    "jvm.gc.max.data.size",
    "jdbc.connections.max",
    "jdbc.connections.min",
    "jvm.memory.committed",
    "system.cpu.count",
    "logback.events",
    "tomcat.global.sent",
    "jvm.buffer.memory.used",
    "tomcat.sessions.created",
    "jvm.threads.daemon",
    "system.cpu.usage",
    "jvm.gc.memory.allocated",
    "tomcat.global.request.max",
    "hikaricp.connections.idle",
    "hikaricp.connections.pending",
    "tomcat.global.request",
    "tomcat.sessions.expired",
    "hikaricp.connections",
    "jvm.threads.live",
    "jvm.threads.peak",
    "tomcat.global.received",
    "hikaricp.connections.active",
    "hikaricp.connections.creation",
    "process.uptime",
    "tomcat.sessions.rejected",
    "process.cpu.usage",
    "tomcat.threads.config.max",
    "jvm.classes.loaded",
    "hikaricp.connections.max",
    "hikaricp.connections.min",
    "jvm.gc.pause",
    "jvm.classes.unloaded",
    "tomcat.global.error",
    "tomcat.sessions.active.current",
    "tomcat.sessions.alive.max",
    "jvm.gc.live.data.size",
    "hikaricp.connections.usage",
    "tomcat.threads.current",
    "hikaricp.connections.timeout",
    "process.files.open",
    "jvm.buffer.count",
    "jvm.buffer.total.capacity",
    "tomcat.sessions.active.max",
    "hikaricp.connections.acquire",
    "tomcat.threads.busy",
    "process.start.time"
  ]
}

Select one of the metrics from this list and append to /actuator/metrics, such as http://localhost:8080/actuator/metrics/http.server.requests. Review the metric details.

{
  "name": "http.server.requests",
  "description": null,
  "baseUnit": "seconds",
  "measurements": [
    {
      "statistic": "COUNT",
      "value": 13
    },
    {
      "statistic": "TOTAL_TIME",
      "value": 0.6496210789999999
    },
    {
      "statistic": "MAX",
      "value": 0.357688147
    }
  ],
  "availableTags": [
    {
      "tag": "exception",
      "values": [
        "None"
      ]
    },
    {
      "tag": "method",
      "values": [
        "GET"
      ]
    },
    {
      "tag": "uri",
      "values": [
        "/actuator/metrics/{requiredMetricName}",
        "/actuator/health",
        "/cities",
        "/**/favicon.ico",
        "/actuator/metrics",
        "/**"
      ]
    },
    {
      "tag": "outcome",
      "values": [
        "CLIENT_ERROR",
        "SERVER_ERROR",
        "SUCCESS"
      ]
    },
    {
      "tag": "status",
      "values": [
        "503",
        "404",
        "200"
      ]
    }
  ]
}

Further, these are multi-dimensional metrics so you can further drill down into them by appending ?tag=key:value at the end of the metric, such as /actuator/metrics/http.server.requests?tag=status:200, such as http://localhost:8080/actuator/metrics/http.server.requests?tag=status:200. Review the metric details.

{
  "name": "http.server.requests",
  "description": null,
  "baseUnit": "seconds",
  "measurements": [
    {
      "statistic": "COUNT",
      "value": 16
    },
    {
      "statistic": "TOTAL_TIME",
      "value": 0.637164562
    },
    {
      "statistic": "MAX",
      "value": 0.004182702
    }
  ],
  "availableTags": [
    {
      "tag": "exception",
      "values": [
        "None"
      ]
    },
    {
      "tag": "method",
      "values": [
        "GET"
      ]
    },
    {
      "tag": "uri",
      "values": [
        "/actuator/metrics/{requiredMetricName}",
        "/actuator/health",
        "/cities",
        "/**/favicon.ico",
        "/actuator/metrics"
      ]
    },
    {
      "tag": "outcome",
      "values": [
        "SUCCESS"
      ]
    }
  ]
}

Stop the cloud-native-spring application.

Deploy cloud-native-spring to Pivotal Cloud Foundry

In order to add full build information to your artifact that is pushed to cloudfoundry, update /cloud-native-spring/pom.xml and add the following execution and classifier to the spring-boot-maven-plugin:

<executions>
    <execution>
        <goals>
            <goal>build-info</goal>
        </goals>
    </execution>
</executions>
<configuration>
    <classifier>exec</classifier>
</configuration>

The full plugin config should look like the following:

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>build-info</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <classifier>exec</classifier>
    </configuration>
</plugin>

Add the following properties to cloud-native-spring/src/main/resources/application.properties.

management.cloudfoundry.skip-ssl-validation=true

Completed:

management.endpoints.web.exposure.include=*
management.info.git.mode=full
management.endpoint.health.show-details=always
management.cloudfoundry.skip-ssl-validation=true

Build the application
```
$ mvn clean package
```
By specifying a classifier we actually just produced 2 jars, one that is executable and one that can be used as an artifact that could be included in other apps (such as our Client UI app we’ll create later). Because of this we need to chance the name of the jar we included in our manifest.yml file. Change the jar in the path property to ./target/cloud-native-spring-0.0.1-SNAPSHOT-exec.jar:
```
---
applications:
  - name: cloud-native-spring
    random-route: true
    memory: 1G
    instances: 1
    timeout: 180 # to give time for the data to import
    path: ./target/cloud-native-spring-0.0.1-SNAPSHOT-exec.jar
    buildpack: java_buildpack_offline
```
Push application into Cloud Foundry
```
$ cf push
```
Find the URL created for your app in the health status report. Browse to your app. Also view your application details in the Apps Mananger UI:
From this UI you can also dynamically change logging levels:

Congratulations! You’ve just learned how to add health data and metrics to any Spring Boot application.

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lab03.adoc

lab03.adoc

Enhancing Boot Application with Metrics

Set up the Actuator

Include Version Control Info

Include Build Info

Health Indicators

Metrics

Deploy cloud-native-spring to Pivotal Cloud Foundry

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lab03.adoc

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Enhancing Boot Application with Metrics

Set up the Actuator

Include Version Control Info

Include Build Info

Health Indicators

Metrics

Deploy cloud-native-spring to Pivotal Cloud Foundry