How to improve Gradle build speed

Fate Chang2016/05/18

Google I/O Extended 2016 Taipei

About me

● Fate Chang● Leopard Mobile● Android developer● Focus on architecture and performance● 1000th member of GCPUG.TW● fb.me/fate.tw● +FateChang

When build is so slow...It’s easily distracted.

Why build so slow

● Slow computer● Not enough memory● Complicate project● Old version tools● Wrong setting● Slow network● ...

We got a chance to try it● Try our Gradle configuration on Mac Pro● Our project CMSecurity release build time around 2 mins.● Can we make it faster?● At this moment Gradle daemon is all I know

Let’s Do It!Step by step

Profiling

● Example project : https://github.com/google/iosched● Checkout from github● Setup baseline

○ $ ./gradlew assembleDebug --dry-run○ Run above command several time ○ Get average time○ Total time: 6.371 secs

--dry-run

● Runs the build with all task actions disabled○ Sometimes you are interested in which tasks are executed in which order

for a given set of tasks specified on the command line, but you don't want the tasks to be executed.

--profile

● $ ./gradlew assembleDebug --dry-run --profile○ --profile parameter will generate profile report page○ Total build time : 7.809s

● $ open build/reports/profile/profile-2016-05-18-15-18-07.html

--configure-on-demand

● $ ./gradlew assembleDebug --dry-run --profile --configure-on-demand

● Total build time : 6.704s

--daemon

● $ ./gradlew assembleDebug --dry-run --profile --configure-on-demand --daemon

● Total build time : 2.663s

Notes of using Gradle daemon

DON’T USE GRADLE DAEMON ON CI.When should I not use the Gradle Daemon

https://docs.gradle.org/current/userguide/gradle_daemon.html#when_should_i_not_use_the_gradle_daemon

How does the Gradle Daemon make builds faster

https://docs.gradle.org/current/userguide/gradle_daemon.html#N1056F

--parallel

● $ ./gradlew assembleDebug --dry-run --profile --configure-on-demand --daemon --parallel

● Total build time : 2.382s

The improvement7.832s -> 2.382s

Other useful Gradle parameter

● --info○ Output more log during build.

● --offline○ Set Gradle to operate without accessing network

resources.○ Note : should remove --offline to check consistency

when library upgraded.● More docs : https://docs.gradle.

org/current/userguide/gradle_command_line.html

How to add parameters in Android Studio

Optimizing Multidex Development Builds

Ref:https://developer.android.com/studio/build/multidex.html#dev-build

Multidex enabled sample project result

Scenario: Clean project and rebuild.

$ ./gradlew clean

$ ./gradlew assembleXxxxx --configure-on-demand --daemon --parallel --offline --info

minSdkVersion 14

Total time: 63.168s secs

minSdkVersion 21

Total time: 52.029 secs

That’s All?

Most recent changes

● Newer Gradle version performance is better○ In 2.13 release notes, measured up to 25% improvements○ Ref : https://docs.gradle.org/2.13/release-notes

● Faster Android Studio Builds with Dex In Process○ Enabled in Android Studio 2.1○ Modify gradle.properties○ org.gradle.jvmargs=-Xmx2048m○ Ref : https://medium.com/google-developers/faster-android-studio-builds-

with-dex-in-process-5988ed8aa37e

Update Gradle Android Plugin Version.

If you upgrade Android Studio to 2.1.x recently, you’ll see this dialog

Note: Update Gradle plugin up to 2.x, Intstant run is default enabled

If yout don’t update in previous dialog, you can update configuration manually.

Update Gradle Android Plugin Version Manually In Android Studio

Android Studio 2.1 new feature

● Dex In Process● This can dramatically increase the speed of

full clean build.● Should update Android plugin version to 2.1.0

as well.

Make dex in process running

If you add dexOptions in build.gradle

You may see this message.

Dex in process not working log

Build with --info parameter

If you see Dexing out-of-process log, it’s not working.

Let’s add setting to gradle.properties

org.gradle.daemon=trueorg.gradle.configureondemand=trueorg.gradle.parallel=trueorg.gradle.jvmargs=-Xmx5120m

Don’t commit these config to version control.or yout can use -Dorg.gradle.jvmargs=-Xmx5120m parameter in command line

Still not working?

Reduce javaMaxHeapSize

Build with --info parameter

If you see Dexing in-process log, you’re all set.

Speed Up In CMSecurity

Build time from 2 mins 20s to less than 1 min. (Tested on MBPR 15” mid 2012 16GB Ram)

Slow in Android Studio but fast in command line?

Try disable Instant Run.

Summary

● Faster CPU is better!● Use latest gradle version (2.13)● Use latest android plugin (2.1.0)● Adjust setting according to your memory● Disable Instant Run, unless you really need it.

One setting won’t fit all, you need to try the combination for best result

Note : Use retrolambda will cause rebuild each time.

References

● 6 tips to speed up your Gradle build○ https://medium.com/@shelajev/6-tips-to-speed-up-your-gradle-build-

3d98791d3df9

● Faster Android Studio Builds with Dex In Process○ https://medium.com/google-developers/faster-android-studio-builds-with-

dex-in-process-5988ed8aa37e