Gradle SummitGradle 3.0: Unleash the Daemon!

Eric Wendelin

2016

Eric Wendelin@eriwen

Long-lived Background Process

Client/Server communicating over TCP locally

Listens for and executes Build Actions

Daemon in a nutshell

Daemonstration

2nd build typically 15-75% faster

faster the more

you use it

Progressive runtime optimizations

Higher class cache hit rate

More effective task I/O caching

"Discovered the beauty of the

@gradle daemon, and now reaping the

benefits of sub-second builds"

@tylerjharden

"Enabling the #gradle daemon took

my build from 13s to 1.1s. This should

be the default."

@GDBolinger

5th build typically 30-90% faster

Smokin'

fast!

Daemon in Gradle 3.0

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

--daemon

org.gradle.daemon=true

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

Resource Awareness

System Memory

Daemon JVM Memory

GC Activity

Other Daemons

What we've built is a framework for making the Daemon more intelligent

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

GRADLE-3018*

GRADLE-3481*

GRADLE-2803

GRADLE-3265

GRADLE-3315

GRADLE-2828

GRADLE-2275*

GRADLE-2415

GRADLE-2629

GRADLE-2367

GRADLE-2273

GRADLE-2271

Reasons not to use the Daemon

* In Progress

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

Better UX

Daemon in Gradle 3.0

Enabled by default

Resource-aware

More robust, especially on Windows

Better UX

Integrated with Gradle Build Scans

Gradle Build Scans

Everyday Daemon Use

When should I use the Daemon?

All projects, everywhereexcept possibly CI

Daemon in IDEs

All IDEs always use the Daemon through the Gradle Tooling API

Reusing Daemons across projects

Same Gradle version

Same $JAVA_HOME

Compatible JVM Args

How do I score one of those sweet,

rare Gradlephant transfer stickers?

Bribery

Maximizing

Performance

Effective Daemon Reuse

gradle --status

gradle --info shows Daemon stopped reasons

org.gradle.daemon.idletimeout

Daemon Performance Logging

org.gradle.daemon.performance.logging=true

~/.gradle/daemon/$VERSION/daemon-$PID.out.log

Daemon Performance Tuning

org.gradle.daemon. performance.tenured-usage-expire-at=90

org.gradle.daemon. performance.tenured-rate-expire-at=1.2

org.gradle.daemon. performance.permgen-usage-expire-at=80

~/.gradle/daemon/$VERSION/daemon-$PID.out.log

Build slow, even with Daemon?

Gradle Build Scans to the rescue

gradle.github.io/performance-guide

Gradle Performance Guide

None of these?

News Flash: You're at the freakin' Gradle Summit

Tweet @gradle

discuss.gradle.org

None of these?

Maximizing Performance

Reuse Daemon as much as possible

Use Build Scans

Gradle Performance Guide

discuss.gradle.org

Beyond Gradle 3.0

Beyond Gradle 3.0

Cross-version Daemon Registry

More intelligent caching

Better cache eviction for longer-running Daemons

Beyond Gradle 3.0

Warms itself up while idle

Automatically adjusts for user behavior through machine learning

Speculative dependency resolution and execution

The Daemon is the vehicle through which Gradle can

become proactive

two more things...

Try it today

gradle wrapper --gradle-version 3.0-milestone-2

Give feedback

discuss.gradle.org

gradle.org/jobs

Have ideas?

@eriwen

Thank You

@mbarnath@ghhale @lhotariEric Wendelin and the Daemon Team

Learn more at www.gradle.org