Improving the performance of Gradle Builds

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Thanks for the feedback and for submitting issues after the Micronaut RC1 release. RC2 will be released early next week. Thus, 1.0.0. stable is around the corner.

This week, I talk about Gradle performance tips and some miscellaneous topics I have encountered.

Gradle

▶Optimize your CI pipeline

Professionally produced video — well-shot, well-edited, high-quality audio — from the Gradle folks.

Key takeaway point for me:

We don't have any complex trigger rules at CI. Any commit triggers the entire pipeline with all of those 20.000 tests. But any given change is unlikely to run all of those because we are using the build cache to avoid doing things like executing tests on a component which has not changed.

Improving the Performance of Gradle Builds

Learn how to identify performance issues with build scans and how to address several areas of you build which may impact performance:

Parallel execution
Configuration
Dependency resolution
Build cache

Stop rerunning your tests

Great rant by @StefanOehme about tests rerun.

Test rerun is the ultimate time waster. Gradle helps you avoid this cost with its build cache and incremental build features. It knows when any of your test inputs, like your code, your dependencies or system properties, have changed. If everything stays the same, Gradle will skip the test run, saving you a lot of time.

Android / iOS

▶ Speeding Up Your Android Gradle Builds (Google I/O '17)

Companion blog post, Optimize your build speed, tips:

Keep your tools up to date
Create a build variant for development
Avoid compiling unnecessary resources
Disable Crashlytics for your debug builds
Use static build config values with your debug build
Use static dependency versions
Enable offline mode
Enable configuration on demand
Create library modules
Create tasks for custom build logic
Convert images to WebP
Disable PNG crunching
Enable Instant Run
Disable annotation processors
Profile your build

Most of these tips, although belonging to the Android world, deal on two main topics. Avoid doing work during configuration phase, leverage build cache.

Misc

Understanding Browser HTTP Accept Headers

Ever wonder what such a value for the Http Header Accept really means:

text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

@KrisJordan explains it perfectly.

An Introduction to ThreadLocal in Java

Last week, I was going into the underworld of Java.

The ThreadLocal construct from the java.lang package gives us the ability to store data individually for the current thread – and simply wrap it within a special type of object.