Love this. cassandra-easy-stress also uses Gradle, fwiw.
On Wed, Apr 29, 2026 at 2:59 PM Isaac Reath <[email protected]> wrote: > +1. We already have Gradle in our build process, it'd be great to make it > first class. > > On Wed, Apr 29, 2026 at 11:06 AM Josh McKenzie <[email protected]> > wrote: > >> *Plus.* >> *One.* >> >> On Tue, Apr 28, 2026, at 7:22 PM, David Capwell wrote: >> >> I'd like to propose adding Gradle build support to the project. This is >> not a proposal to remove ant -- ant remains the primary build system. The >> patch (PR #4778) adds gradle as an opt-in developer tool that sources its >> configuration from ant's build.xml, layering gradle's task graph and >> caching on top of what we already have. >> >> **What the patch does** >> >> Gradle wraps ant's existing configuration. You maintain ant as before; >> gradle reads from it. The result is a developer experience layer on top of >> our current build: >> >> ``` >> $ ./gradlew test --tests org.apache.cassandra.utils.UUIDTest --rerun >> BUILD SUCCESSFUL in 2s >> 27 actionable tasks: 1 executed, 26 up-to-date >> ``` >> >> Compare this to the correct way to run a single test via ant that matches >> what CI actually executes and doesn't rebuild unneeded work: >> >> ``` >> $ # human validates that the cache is still valid... did you change the >> JDK? Did any file change? Human must maintain this in their head >> $ ant -Dant.gen-doc.skip=true \ >> -Dno-checkstyle=true \ >> -Dant.gen-doc.skip=true \ >> -Drat.skip=true \ >> -Dno-build-test=true \ >> testclasslist \ >> -Dtest.timeout=480000 \ >> -Dtest.classlistprefix=unit \ >> -Dtest.classlistfile=<(echo org/apache/cassandra/utils/UUIDTest.java) >> ``` >> >> Most developers use `ant test-some` instead because of this complexity, >> but `test-some` uses different JVM arguments than `testclasslist` (which is >> what CI runs). This means test failures in CI may not reproduce locally >> because the developer ran the test differently. With gradle there is one >> way to run a test; local and CI do not have different behaviors. >> >> **Why Gradle and not Maven** >> >> This question has come up in every prior discussion, so let me address it >> directly. >> >> 1. **The ecosystem already chose Gradle.** Accord, Sidecar, and Analytics >> are all Gradle projects. Choosing Maven for the server would mean three >> subprojects on Gradle and one on Maven. Accord integration is the clearest >> example of the problem: today, ant works around Accord being a Gradle >> project by having Accord *publish* artifacts to the user's local Maven >> repository, then ant resolves them from there. Maven would have the same >> problem -- it would also need Accord to publish locally before the server >> build can proceed. With Gradle, there's no publish step at all. Gradle >> understands how to build Accord directly via composite builds: >> >> ```groovy >> includeBuild('modules/accord') { >> dependencySubstitution { >> substitute module('org.apache.cassandra:cassandra-accord') >> using project(':accord-core') >> } >> } >> ``` >> >> Gradle builds Accord from source as part of the server build. No >> intermediate publish, no stale local artifacts, no coordination. >> >> 2. **Maven forces us into its model; Gradle lets us keep ours.** Over the >> years with ant we've grown a number of custom solutions to problems -- >> custom test execution, custom artifact assembly, custom dependency >> handling. These work for us. Maven's opinionated structure (one artifact >> per POM, standard lifecycle phases, rigid directory layout) would require >> us to restructure the project to fit Maven's expectations. We'd be fighting >> the tool. Gradle lets us express our existing custom workflows naturally >> while still benefiting from a modern build system's caching, dependency >> resolution, and task graph. >> >> 3. **Maven can't wrap ant.** The approach in this patch -- gradle >> sourcing ant's config so we incrementally adopt without a big-bang rewrite >> -- isn't possible with Maven. A Maven migration would require rewriting >> build configuration from scratch, which is exactly the kind of disruption >> that has killed every prior proposal on this mailing list. >> >> 4. **Incremental builds are first-class in Gradle.** Maven's incremental >> story requires plugins and is unreliable in practice. Gradle's task >> avoidance and build cache are core features. >> >> 5. **Gradle version stability -- an honest assessment.** The concern >> about Gradle version churn is legitimate. We pin a specific version via the >> wrapper (Gradle 9 in this patch), so day-to-day there is no drift. However, >> when we do need to upgrade -- for example, to pick up JDK support for a new >> Java version -- there is real risk of breaking changes requiring work. If >> we release annually, we may need to update Gradle annually, and that could >> require effort. >> >> Two things that mitigate this: First, Gradle has improved its >> deprecation cycle -- they warn for a full major version before removing >> APIs, giving upgrade windows. This patch already addressed Accord's Gradle >> 8 to 9 migration, which involved deprecation warnings (not breakage) that >> will become errors in 10.x. Second, AI tooling dramatically lowers the >> migration cost. This patch itself was written by Claude opus and it had no >> issues understanding Gradle's conventions and generating the correct >> configuration. Future version upgrades are well-suited to the same approach >> -- the tool reads the migration guide, reads our config, and produces the >> update. >> >> **Maintenance cost** >> >> I want to be clear-eyed about this: "gradle sources ant" means there is >> minimal maintenance overhead *for the current project structure*. If we had >> this patch 5 years ago, there would have been zero drift in that time. But >> it's not zero-maintenance in all scenarios -- if we want to do larger >> structural changes (splitting into multiple modules, reorganizing source >> sets), both systems would need updates. For the day-to-day reality of how >> the project evolves, though, the cost is very low. >> >> **The long-term path** >> >> If gradle proves itself I foresee that we eventual rely on gradle as the >> source of truth for builds and we update ant to delegate to gradle. If the >> community eventually feels that gradle is getting in our way its isolated >> and able to revert; so very low risk. >> >> **What's in this patch and what isn't** >> >> The patch covers the core developer loop: >> >> - Main source compilation with correct JDK flags and `--add-exports` >> - Dependency resolution from existing POM files >> - ANTLR 3 and JFlex code generation >> - Unit, long, burn, distributed, and simulator test suites with correct >> JDK-specific JVM args >> - All 5 test variants (compression, cdc, latest, oa, >> system-keyspace-directory) >> - Checkstyle (main + test) >> - Main JAR and simulator JARs >> - Accord composite build (no local publish step) >> >> What's not covered yet: >> >> | Category | What's Missing | >> |---|---| >> | Packaging | stress.jar, fqltool.jar, sstableloader.jar, dtest-jar, >> sources-jar, javadoc-jar | >> | Release | bin/src tarballs, checksums, dist directory assembly | >> | Publishing | Maven local install and remote deploy with signing | >> | Test suites | upgrade dtests, memory tests, >> stress/fqltool/sstableloader tests, CQL-specific tests | >> | Code coverage | JaCoCo integration | >> | Documentation | Javadoc, Asciidoc/Antora | >> | Benchmarks | JMH microbench | >> | Static analysis | Apache RAT license check | >> | Security scanning | OWASP, SonarQube | >> >> This is roughly 52% of ant's total logical outcomes. The intentional >> scoping choice was: cover what developers actually use daily, get buy-in on >> the approach, then fill in the rest. I'm happy to add any of the above -- >> particularly release/publishing support -- once the direction is agreed. >> None of these are architecturally difficult; they're just additional tasks >> to wire up. >> >> **Patch details** >> >> - JIRA: https://issues.apache.org/jira/browse/CASSANDRA-21344 >> - PR: https://github.com/apache/cassandra/pull/4778 >> >> Looking forward to feedback. >> >> --- >> >> **Prior mailing list discussions referenced:** >> >> - "[DISCUSS] Build tool" (Feb 2022) -- Aleksei Zotov's proposal to >> migrate from ant >> - "RFC try for s/ant/gradle/" (Sep 2014) -- Robert Stupp's original >> Gradle proposal and prototype >> - "[discuss] Modernization of Cassandra build system" (Jun 2015) >> - "[DISCUSS] CASSANDRA-17750: Security migration away from Maven Ant >> Tasks" (Aug 2022) >> - "Any plan to migrate from Ant to Maven?" (May 2020) >> >> >>
