Monthly summary for 2025-10 — eclipse-openj9/openj9 Overview: This month focused on modernizing Java Unsafe API usage to improve Java 23+ compatibility, cleaning the test suite to boost CI efficiency, hardening builds across AIX and Windows, and addressing a critical stability issue in error reporting. Delivery across four areas delivered measurable business value: compatibility, test reliability, platform robustness, and crash-reporting safety.

September 2025 highlights across the OpenJ9 family, with cross-repo delivery focusing on branding modernization, security/compatibility upgrades, cross-platform stability, enhanced diagnostics, and expanded test coverage for newer JDKs. The work reduces onboarding friction, strengthens security posture, and improves reliability across Windows, Linux, AIX, and PowerPC environments, enabling faster validation and higher confidence in releases.

August 2025 focused on stabilizing and accelerating the OpenJDK/OpenJ9 ecosystem across two repositories, delivering CI/build enhancements, critical bug fixes, and expanded cross-platform test coverage to reduce flaky builds and shorten feedback cycles.

Month: 2025-07 Summary: This period delivered cross-repo improvements across the Eclipse OpenJ9 ecosystem, delivering build reliability, runtime diagnostics, and test stability that reduces friction for developers and accelerates release readiness. Key features delivered: - Cross-repo build and platform reliability improvements: revert CMake minimum version to 3.4/3.5 and update AIX tooling, ensuring consistent builds across environments for OpenJ9 and OMR; related boot JDK updates for AIX. (Commits include a8cc37f4e96188e4ba741f4b3b04ec1b12a2fe09, 9822b258994fcd96850849c2fd2b041eb91c05ad, 59ac2f4e94aba4698f1ecceb692f9b5f28108094) - VM diagnostics and runtime visibility enhancements: native class file version retrieval for JDK 20+ with Valhalla; CPU features API; expanded buffers to avoid truncation, enabling faster troubleshooting and runtime analysis. (Commits: 857949a4e4e330a18770cc7ac2d45d060609b9e0, 4d4358e40e140f4a24d7acc4b3ab515aedc7d19b, f1ad5a977e2478021c5c117125e1c06bc556eee7) - Localization improvements: refined diagnostic message translations with new strings for dump processing events and timing. (Commit: 7e7e25f6ea33261753582872d53e8589fba6de83) - Test stability and CI hardening: stabilize test suite by excluding problematic AIX tests, preventing core dumps during OOM testing, and reintroducing a test utility to validate XML outputs. (Commits: 3f07e362a7f34229ee5c2df88261c6d3f9a21492, 96b6fb3ae922d19f2346135167da1f3b274049e6, b8e0b3c2e439662c26634381c250af64152f72f0) - AIX platform robustness and reporter accuracy: improved AIX library loading by ensuring shared archive members load correctly when the decorate flag is absent and cleaner system feature reporting by filtering unknown values. (Commits: 1f13c07baf48df5d404e8a55e67680c7c1b8812d, 8225c0645203f60924d4b8f9828a93aa89a4e8b9) Major bugs fixed: - Excluded problematic AIX tests and prevented core creation for intentional OOM scenarios, reducing flaky test runs and improving CI reliability. (Commits: 3f07e362a7f34229ee5c2df88261c6d3f9a21492, 96b6fb3ae922d19f2346135167da1f3b274049e6, b8e0b3c2e439662c26634381c250af64152f72f0) - AIX-specific library loading robustness and environment reporting cleanup to prevent false negatives in diagnostics. (Commits: 1f13c07baf48df5d404e8a55e67680c7c1b8812d, 8225c0645203f60924d4b8f9828a93aa89a4e8b9) Overall impact and accomplishments: - Reduced platform-specific build and test flakiness, enabling faster, more reliable releases across Linux, AIX, and other target environments. Enhanced runtime visibility and diagnostics directly support faster issue resolution and better performance tuning. Strengthened QA processes with targeted exclusions and vector-test framework improvements to maintain high stability for JDK 25 OpenJ9. Technologies/skills demonstrated: - Build tooling and platform engineering (CMake, AIX toolchain, JDK boot environments) - VM internals and diagnostics (native methods, class file versioning, CPU feature exposure) - Localization and internationalization (NLS translations) - Test engineering and CI reliability (test exclusion management, OOM handling, XML validation utilities) - OpenJ9/OMR internals, AIX platform behavior, vector test frameworks

June 2025 monthly summary for eclipse-openj9/openj9: Focused on modernizing the build toolchain for Java 25/26 and CMake, improving internationalized error messages, and stabilizing API behavior. Delivered a cleaner, more maintainable toolchain, improved CI/CD alignment, and preserved runtime correctness while enabling faster onboarding to newer Java targets.

May 2025 performance summary: Cross-repo delivery across eclipse-openj9/openj9, eclipse-openj9/openj9-omr, and adoptium/aqa-tests focused on stabilizing multi-arch builds, hardening security, and improving release readiness. Key outcomes include enabling 32/31-bit builds on AIX and z/OS, enforcing noexecstack on Linux, and stabilizing OpenJDK 11 on OpenJ9 with targeted test exclusions, while streamlining build infra and release documentation.

April 2025 monthly summary: Cross‑platform stability and CI reliability improvements across the aqa-tests and OpenJ9 ecosystems. Key features delivered include (1) OpenJ9 build system stabilization across 32/64-bit targets, with 32-bit memset warning handling, Jenkins JDK alignment, removal of obsolete plinux specs, and a linux_390 CMake cache to support pointer-sized formatting; (2) CI artifact retention policy improvements to balance storage efficiency and accessibility, raising daysToKeepArtifacts to 27 across Nightly, Release, OMR, and OpenJDK builds; (3) OpenJ9-OMR enhancements enabling 32-bit x86 object format elf32 and 31-bit s390 compilation support; (4) Localization updates to reflect deprecation messaging for java.compiler warnings. Major bugs fixed include (a) OpenJ9 Test Suite Stability enabling testing progress through temporary exclusions (ValidateISO4217 in OpenJDK 8) and platform-specific exclusions (Collectable.java for JDK21 on OpenJ9) with subsequent restoration; (b) GC stability and verbose output robustness by reinstating previous off-heap behavior and handling NULL translations in gcDumpQualifiedSize; (c) Monitor/VM threading restoration by reverting the detach-related VM thread retrieval change; (d) NLS/deprecation messaging corrections to refine user guidance. Overall impact: reduced flaky tests, improved cross‑platform compatibility, more predictable CI cycles, and clearer guidance to users. Technologies/skills demonstrated: cross‑platform build systems (CMake), 32/64-bit compilation and platform-specific tuning, NASM/elf32 handling, 31-bit s390 support, GC diagnostics and tuning, and localization workflows.

In March 2025, stability and modernization were delivered across three repos: adoptium/aqa-tests, eclipse-openj9/openj9, and adoptium/temurin-build. Key outcomes include stabilizing OpenJ9 test runs with Windows and cross-version exclusions, refining exclusion policy (Entrust.java; removing outdated TimestampCheck), modernizing Java system properties initialization and GetProperties integration for JDK 11–17, and enforcing UTF-8 as the default console encoding with cleanup of platform encoding logic. Additional stability and build-environment upgrades included AOT feature detection revert for xcr0, off-heap memory revert for certain architectures, targeted Linux test gating, documentation cleanup, and an OpenSSL 3.0.16 upgrade in the Temurin build workflow. Overall, these efforts reduced flaky failures, improved CI reliability, and strengthened the foundation for secure, scalable Java builds.

February 2025 monthly summary focused on cross-repo build reliability, modernization, and test stability across OpenJ9 and AQA-tests. Delivered key features, addressed critical bugs, and reinforced cross-platform support with an emphasis on business value and maintainability.

January 2025 performance summary focused on stabilizing build/test pipelines, improving security posture, and enabling developer onboarding. Delivered targeted updates to Windows build setup, hardened OpenSSL dependencies, and advanced test stabilization efforts across the OpenJ9 and AQA test suites. Resulted in lower build/test churn, quicker feedback cycles, and more reliable platform coverage.

Month: 2024-12 Monthly Summary Overview: Delivered cross-version Java compatibility, stability improvements, and broader platform coverage across the OpenJ9 stack. Focused on reducing customer risk through robust test stability, clearer error handling, and enhanced OS/version recognition. Technical work spanned three repositories, with targeted commits that tightened security surface exposure, improved localization for GC options, and preserved coverage for CipherMode on AIX alongside NULL-safe string conversions. Key features delivered (business value in parentheses): - JDK version compatibility and test stability improvements in eclipse-openj9/openj9: Cleanup of dead ReferenceQueue methods for JDK 19+ and test stability adjustments for JDK 8 xlinux to maintain compatibility across Java versions, reducing cross-version test failures. Commits: 9f5f6b0526f6687f873b9c22b6b97eaf2bbc102b; 74a26c1d36e5f858f6d02fe4078d4e2a4ee2e8f4 - JDK21 compatibility exposure: Exposed System.allowSecurityManager in java.lang.Access for JDK 21, enabling correct exposure and conditional compilation by Java spec versions. Commit: 7cb76fd85c005b357824341802ca15ec94ae15d2 - Localization updates for j9gc: Added latest NLS translations for unsupported GC options, ensuring clearer user messages and policy alignment. Commit: 6a845a61e88e00cbc3339b62721f898cafa0abc4 - OS/version recognition: Windows Server 2025 support in System Information Utility by recognizing builds 26100+, broadening platform coverage. Commit: 545645f3973b0253444b5ca4329398207c94ae04 - NULL-safe string conversions: NULL input handling for a2e_string/e2a_string with NULL safety and NULL-friendly error reporting to prevent crashes. Commit: dc5017ad2d6bbfa58f7d5d78566917f6280d323a - CipherMode test coverage on AIX: Adjusted gating to restore coverage for CipherMode across OpenJ9 JDK17/21 on AIX (exclusion and revert). Commits: 5199075575eb0e6b330a51d97be81a08b9285ac3; c58973bc2a9d80420c5ec8c06f97a15591fcb74f Major bugs fixed: - Cleaned up dead ReferenceQueue methods and tuned test exclusions to stabilize JDK 19+ and JDK8 xlinux test environments. (commits listed above) - Fixed crashes by handling NULL inputs in string conversion utilities and updating error reporting accordingly. (dc5017ad...) - Restored CipherMode test coverage on AIX by re-enabling tests after initial exclusion, ensuring coverage across JDK17/21. (51990755..., c58973bc...) Overall impact and accomplishments: - Reduced cross-version risk and improved test reliability for OpenJ9 across Java versions and platforms (Linux/x86_64, AIX, Windows Server). - Expanded platform visibility with Windows Server 2025 recognition and improved OS detection surfaces. - Strengthened security exposure surface for JDK21 while maintaining compatibility across specs. - Improved user-facing messaging and stability through up-to-date translations and NULL-safe utilities. Technologies/skills demonstrated: - Java/JDK compatibility, OpenJ9 and OMR integration, AIX and Windows Server platform considerations. - Localization/Internationalization (NLS) updates, NULL safety in C/C++-level utilities, and test governance for CipherMode.

Month: 2024-11. This period delivered security hardening, debugging observability improvements, robustness enhancements, diagnostics/localization upgrades, and CRaC readiness work across eclipse-openj9/openj9-omr, eclipse-openj9/openj9, and adoptium/aqa-tests. The changes emphasize business value: reduce risk of crashes and vulnerabilities, accelerate issue triage, improve user-facing error messaging, and prepare for future CRaC management capabilities.

Monthly summary for 2024-10 for eclipse-openj9/openj9: concise delivery highlights, impact, and technical skills demonstrated.