Maximizing Developer Productivity
with Gradle and Maven

Jenn Strater, Gradle @codeJENNerator

Who am I?

speaker {
    name = "Jennifer 'Jenn' Strater"
    currentHome = "Berlin, Germany"
    nationality = 'USA'
    company = "Gradle"
    title = "Developer Advocate"
    contributorTo = [
        "Spring REST Docs",
        "Codenarc",
        "Apache Groovy Community",
        "GR8DI"
    ]
    twitter = "@codeJENNerator"
    github = "jlstrater"
    web = uri("https://www.jennstrater.com")
}

Gradle

Build automation

Development productivity
(Gradle & Maven)

Why is Developer Productivity important?

Long developer cycles → longer to get to production
More time waiting → less times to develop features
Context switching → more time to work on each feature

How are builds critical to Developer Productivity?

inefficient builds take longer to run
when build take too long there can be context switching
non-reproducable builds can cause problems at the least convenient times

Waiting

One extra minute per build destroys 4% of engineering capacity, on average.

Lost Time on Debugging

Debugging Time

On average, 20% of all builds fail because of code defects.
This easily adds up to 5-10% of engineering capacity.
Netflix has done internal studies that show that this consumes 20% of their engineering capacity.

How many builds are you running?

Gradle Team Example

Faster builds

How do we get faster?

What is slow?

https://enterprise-training.gradle.com/s/rzht6qise5ujg

Getting Started with Build Scans

Gradle

$> gradle build --scan
...
BUILD SUCCESSFUL in 5s
143 actionable tasks: 29 executed, 76 from cache, 38 up-to-date

Publishing build scan...
https://gradle.com/s/wnftgsuyjleyi

Gradle Build Scan Plugin

plugins {
  id "com.gradle.build-scan" version "2.3"
}

buildScan {
  server "https://gradle-enterprise.yourcompany.com"
  publishAlways()
}

Maven

(Register the Extension in .mvn/extensions.xml)

<extensions>
  <extension>
    <groupId>com.gradle</groupId>
    <artifactId>gradle-enterprise-maven-extension</artifactId>
    <version>1.1.4</version>
  </extension>
</extensions>

Maven

$> mvn clean verify
...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  5.262 s
[INFO] Finished at: 2019-04-23T09:55:36+02:00
[INFO] ------------------------------------------------------------------------
[INFO] 13 goals, 8 executed, 5 from cache, saving at least 16s
[INFO]
[INFO] Publishing build scan...
[INFO] https://gradle.com/s/ypgljbvelzxzs
[INFO]

Maven

«project»/.mvn/gradle-enterprise.xml

<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.yourcompany.com</url>
  </server>
  <buildScan>
    <publish>ALWAYS</publish>
  </buildScan>
</gradleEnterprise>

Build Scans – Demo

https://enterprise-training.gradle.com/s/rzht6qise5ujg

How do we get faster?

More efficient use of resources
Don’t rebuild what hasn’t changed
Run builds efficiently
Fix failures faster

How do we get faster?

More efficient use of resources
Don’t rebuild what hasn’t changed
Run builds efficiently
Fix failures faster

Resource usage

Settings & Suggestions

Switches

Gradle

Maven

Infrastructure

Gradle

Maven

Resources

How do we get faster?

More efficient use of resources
Don’t rebuild what hasn’t changed
Run builds efficiently
Fix failures faster

Incremental Builds

https://blog.gradle.org/introducing-incremental-build-support

How does the Build Cache work?

The cacheKey for Tasks/Goals is based on the Inputs:
cacheKey(javaCompile) = hash(sourceFiles, …)
The cacheEntry contains the output:
cacheEntry[cacheKey(javaCompile)] = fileTree(classFiles)

userguide/build_cache.html#sec:task_output_caching

Build Cache for Gradle (single run)

$> gradle --build-cache assemble
:compileJava FROM-CACHE
:processResources
:classes
:jar
:assemble

BUILD SUCCESSFUL

Build Cache for Gradle (all)

Set org.gradle.caching=true in gradle.properties

Build Cache for Gradle

By default in Java, Groovy, Scala, C++ und Swift
Supports tasks such as Compile, Javadoc, Test und Verification

userguide/build_cache.html#sec:task_output_caching_cacheable_tasks

Build Cache for Maven

Requires the Gradle Enterprise Maven Extension
Only supported for clean builds
Initial Release: March 2019
Supported Plugins: Java Compiler, Surefire/Failsafe, Javadoc, JAXB, Checkstyle, and more!

https://docs.gradle.com/enterprise/maven-extension/#cacheable_plugins_and_goals

Build Cache – Demo

These slides as a Gradle project

(with a detour into how Gradle esp. Kotlin DSL works)

Storing

Cache Hit

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Remote cache configuration (Gradle)

settings.gradle

buildCache {
    remote(HttpBuildCache) {
        url = 'https://gradle-enterprise.yourcompany.com/cache/'
    }
}

Conditional cache configuration (Gradle)

settings.gradle

def ciServer = System.getenv().containsKey('CI')

buildCache {
    local {
        enabled = !ciServer
    }
    remote(HttpBuildCache) {
        url = 'https://gradle-enterprise.yourcompany.com/cache/'
        push = ciServer
    }
}

Remote cache configuration (Maven)

<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.yourcompany.com</url>
  </server>
</gradleEnterprise>

Per project: «project»/.mvn/gradle-enterprise.xml
Per user: ~/.m2/gradle-enterprise.xml.

Conditional cache configuration (Maven)

<gradleEnterprise>
  <server>
    <url>https://gradle-enterprise.yourcompany.com</url>
  </server>
  <buildCache>
    <remote>
      <storeEnabled>false</enabled>
    </remote>
  </buildCache>
</gradleEnterprise>

./mvnw clean assemble -Dgradle.cache.remote.storeEnabled=true

Cache Administration

Pause

How do we get faster?

More efficient use of resources
Don’t rebuild what hasn’t changed
Run builds efficiently
Fix failures faster

Learn the build tools

Gradle

https://docs.gradle.org/current/userguide/what_is_gradle.html

Behavioral changes

Gradle users should stop running clean!
Yes, even for CI.

Only run the tasks you need.

Use dependency caching.

Fail tests as soon as possible

test {
    failFast = true
}

gradle integTest --fail-fast

Dependency Conflicts

Use Gradle ;)

How do we get faster?

More efficient use of resources
Don’t rebuild what hasn’t changed
Run builds efficiently
Fix failures faster

Extending build scans

Extending build scans (Gradle)

build.gradle

def ciServer = System.getenv().containsKey('CI')

buildScan {
  tag(ciServer ? "CI" : "local")
  value("buildNumber", 2)
  link("CI Build", "http://ci-server/build/2")
}

Or via system properties:
./gradlew build -Dscan.tag.CI

Extending build scans (Maven)

pom.xml

<plugins>
  <plugin>
    <groupId>org.gradle</groupId>
    <artifactId>gradle-enterprise-maven-extension</artifactId>
    <version>1.1.4</version>
    <configuration>
      <gradleEnterprise>
        <buildScan>
          <tags><tag>CI</tag></tags>
          <links><link><name>CI Build<name><url>http://ci-server/build/2</url></link></links>
          <values><value><name>buildNumber<name><value>2</value></value></values>
        </buildScan>
      </gradleEnterprise>
    </configuration>
  <plugin>
</plugins>

Or via system properties:
./mvnw package -Dscan.tag.CI

Extending build scans (Maven)

Complex logic can be implemented as a Groovy script

<plugin>
  <groupId>org.codehaus.gmavenplus</groupId>
  <artifactId>gmavenplus-plugin</artifactId>
  <version>1.6.2</version>
  <executions>
    <execution>
      <id>build-scan-user-data</id>
      <phase>validate</phase>
      <goals>
        <goal>execute</goal>
      </goals>
    </execution>
  </executions>
  ...

Extending build scans (Maven)

  <configuration>
    <scripts>
      <script>file:///${project.basedir}/buildScanUserData.groovy</script>
    </scripts>
  </configuration>
  <dependencies>
    <dependency>
      <groupId>org.codehaus.groovy</groupId>
      <artifactId>groovy-all</artifactId>
      <version>2.5.6</version>
      <type>pom</type>
      <scope>runtime</scope>
    </dependency>
  </dependencies>
</plugin>

Extending build scans (Maven)

buildScanUserData.groovy

def buildScan =
  session.lookup("com.gradle.maven.extension.api.scan.BuildScanApi")

def ci = System.getenv('CI')
if (ci) {
  buildScan.tag('CI')
} else {
  buildScan.tag('Local')
}

Collaboration through Deep Linking

Build Comparison

Compare two builds

Input volatility

Inputs need to be stable and portable
Common problems:
- Timestamps
- Absolute file paths
- Non-deterministic ordering

Volatile inputs

Runtime classpath normalization

Inconsequential & volatile files on runtime classpaths can be ignored.

More cache hits and faster builds.

Runtime classpath normalization

Inconsequential & volatile files on runtime classpaths can be ignored.

More cache hits and faster builds.

Runtime classpath normalization (Gradle)

build.gradle

normalization {
    runtimeClasspath {
        ignore 'build-info.properties'
    }
}

Runtime classpath normalization (Maven)

pom.xml

<plugin>
  <groupId>com.gradle</groupId>
  <artifactId>gradle-enterprise-maven-extension</artifactId>
  <version>1.1.4</version>
  <configuration>
    <gradleEnterprise>
      <normalization>
        <runtimeClassPath>
          <ignoredFiles>
            <ignoredFile>META-INF/build.properties</ignoredFile>
          </ignoredFiles>
        </runtimeClassPath>
      </normalization>
    </gradleEnterprise>
  </configuration>
</plugin>

Gradle is a Data Platform

Performance Dashboard

Trends Dashboard

Do your own build data analysis

Gradle Enterprise exposes build scan data for real time consumption via API

Export API Example

https://github.com/gradle/build-analysis-demo

Trial

Request a free 30-day trial at https://gradle.com/enterprise/trial.

Resources

Free Trainings at gradle.com/training:
- Introduction to Gradle
- Build Cache Deep Dive
- Maven + Gradle Enterprise
Gradle Build Tool Docs: https://docs.gradle.org
Gradle Enterprise Docs & Tutorials: https://docs.gradle.com
Free build scans for Maven & Gradle: https://scans.gradle.com
Gradle Newsletter: https://newsletter.gradle.com

Conclusion

Measure your builds!
Analyze the data for both local and CI builds.
Improve build processes using build automation tooling.
Optimize builds with incrementalization and/or parallelization.
Iterate to maintain build happiness.

Questions?

jenn@gradle.com codeJENNerator
Jennifer Strater

Maximizing Developer Productivitywith Gradle and Maven

Who am I?

Gradle

Why is Developer Productivity important?

How are builds critical to Developer Productivity?

Waiting

Lost Time on Debugging

Debugging Time

How many builds are you running?

Gradle Team Example

Faster builds

How do we get faster?

How do we get faster?

What is slow?

Getting Started with Build Scans

Gradle

Gradle Build Scan Plugin

Maven

Maven

Maven

Build Scans – Demo

How do we get faster?

How do we get faster?

Resource usage

Settings & Suggestions

Switches

Infrastructure

Resources

How do we get faster?

Incremental Builds

How does the Build Cache work?

Build Cache for Gradle (single run)

Build Cache for Gradle (all)

Build Cache for Gradle

Build Cache for Maven

Build Cache – Demo

Storing

Cache Hit

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Local and Remote Cache

Remote cache configuration (Gradle)

Conditional cache configuration (Gradle)

Remote cache configuration (Maven)

Conditional cache configuration (Maven)

Cache Administration

Cache Administration

Pause

How do we get faster?

Learn the build tools

Gradle

Behavioral changes

Fail tests as soon as possible

Dependency Conflicts

Use Gradle ;)

How do we get faster?

Extending build scans

Extending build scans (Gradle)

Extending build scans (Maven)

Extending build scans (Maven)

Extending build scans (Maven)

Extending build scans (Maven)

Collaboration through Deep Linking

Build Comparison

Compare two builds

Input volatility

Volatile inputs

Runtime classpath normalization

Runtime classpath normalization

Runtime classpath normalization (Gradle)

Runtime classpath normalization (Maven)

Gradle is a Data Platform

Performance Dashboard

Trends Dashboard

Maximizing Developer Productivity
with Gradle and Maven