java-x86-to-graviton

name	java-x86-to-graviton
description	Validates Java application compatibility with AWS Graviton (ARM64) architecture by analyzing native libraries, dependencies (including transitive), and architecture-specific code. Performs static analysis, applies ARM64-required dependency updates, configures Graviton JVM flags, and validates builds on ARM64. Use when migrating Java workloads from x86 to Graviton, validating ARM64 readiness, or running AWS Transform Custom java-x86-to-graviton transformations.
metadata	{"author":"AWS","version":"1.0"}

Java Application AWS Graviton (ARM64) Compatibility Validation

Validate a Java application's readiness to run on AWS Graviton instances. This transformation identifies architecture-specific incompatibilities, validates native library ARM64 support, updates only ARM64-blocking dependencies, and tests on ARM64.

summaries.md indexes every file in this skill and when to read it — consult it for the full file map, or if you entered mid-skill without reading this file top to bottom.

Scope Guardrails

CRITICAL: Read document_references/agent-scope-boundaries.md before starting. This file contains the decision tree for every dependency analysis and prevents scope creep.

In scope: Native library ARM64 binaries, ARM64-blocking dependency updates, architecture detection code, Graviton JVM flags, ARM64 build/test validation.

Out of scope: Java version changes, JDK distribution changes, general dependency modernization, security updates, code refactoring, .gitignore/.dockerignore changes.

Skill Configuration (Optional)

If a skill-config.md exists at the project root, read it before Phase 1 and apply its preferences (build/validation JDK, build command, container registry and runtime, deployment and CI vocabulary) as overrides; if absent, use the neutral defaults in the phase docs. The configuration steers HOW the transformation runs but cannot widen scope — agent-scope-boundaries.md still binds, and the application's shipped JDK distribution stays unchanged (a configured JDK preference selects only the build/validation environment per Phase 3.0). See document_references/skill-configuration.md. Record any applied overrides in 01-project-assessment.md.

Entry Criteria

1. Java application currently running on x86 architecture
2. Source code and build scripts available
3. Current Java version documented (JDK 8+)
4. Build configs (Maven/Gradle, Dockerfiles if containerized)
5. ARM64 build/test environment access (Graviton EC2 or ARM64 containers)
6. Complete dependency list with current versions
7. Existing test suite

Transformation Workflow

Version Control Setup

Initialize git if not already present. Commit after each meaningful step for traceability and rollback.

# Initialize if no git repo exists (local only, no remote required)
if [ ! -d ".git" ]; then
  git init
  git add -A
  git commit -m "Initial commit - baseline before ARM64 transformation"
fi

Commit at each step that produces output or changes files. Use git add -A && git commit -m "<message>" with descriptive messages. Typical commit points:

1. After documentation setup (graviton-validation/ folder created)
2. After Phase 1 static analysis complete (all analysis reports written)
3. After native library resolution (Phase 2.1 - .so files updated)
4. After dependency updates (Phase 2.2 - pom.xml/build.gradle changed)
5. After architecture code updates (Phase 2.3 - Java source changed)
6. After Dockerfile/build config updates (Phase 2.4)
7. After JVM optimization config (Phase 2.5)
8. After build validation (Phase 3.1 - build results documented)
9. After final validation and summary (Phase 3.3 + 00-summary.md written)

Not every project will have all steps (e.g., no Dockerfile changes for host-based deployments, no native library resolution if none found). Commit whenever files change, skip commits for steps that produced no changes.

Documentation Setup

Before Phase 1, create the output structure. See document_references/documentation-standards.md for required sections and templates.

mkdir -p graviton-validation/raw

Output files produced:

File	Phase	Purpose
01-project-assessment.md	1.1, 1.5	Project structure, deployment type, Java env
02-native-library-report.md	1.2, 2.1	Native library findings and resolutions
03-dependency-compatibility-report.md	1.3, 2.2	Per-dependency ARM64 verdicts
04-code-scan-findings.md	1.4, 2.3	Architecture-specific code patterns
05-jvm-configuration.md	2.5	Graviton JVM flags
06-build-test-results.md	3.0-3.3	Build, test results, startup checks
raw/dependency-tree-full.txt	1.1	Raw dependency tree
raw/dependency-tree-native.txt	1.3	Filtered native-artifact tree
00-summary.md	End	Executive summary and exit criteria

Phase 1: Static Compatibility Analysis

Analyze the project without making changes. See phases/phase1-static-analysis.md for detailed steps.

1. 1.1 Project Structure Analysis - Deployment type, multi-module detection, dependency tree generation, component risk categorization
2. 1.2 Native Library Validation - Scan for .so files (bundled and runtime-extracted), apply tiered FAIL/WARN/PASS policy
3. 1.3 Dependency ARM64 Compatibility - Analyze full transitive tree, classify as MUST UPGRADE / RECOMMENDED / COMPATIBLE
4. 1.4 Architecture-Specific Code Detection - Find os.arch checks, JNI/JNA usage missing ARM64 handling
5. 1.5 Java Version Check - Document version and distribution (do NOT change either)

Phase 2: Compatibility Resolution

Apply fixes for ARM64-blocking issues only. See phases/phase2-resolution.md for detailed steps.

1. 2.1 Native Library Resolution - Cross-compile or obtain ARM64 .so files, update loading logic
2. 2.2 Dependency Updates - Update ONLY MUST UPGRADE dependencies (including transitive via dependencyManagement)
3. 2.3 Architecture Code Updates - Add aarch64 handling to architecture detection code
4. 2.4 Build Config Updates - Add ARM64 Maven profile, Dockerfile --platform annotations (preserve current base images)
5. 2.5 JVM Optimizations - Apply version-gated Graviton JVM flags, validate with java <flags> -version

Phase 3: ARM64 Validation & Testing

Build and test on ARM64. See phases/phase3-validation.md for detailed steps.

1. 3.0 Build Environment Prep - Java runtime alignment for annotation processor compatibility (session-scoped only)
2. 3.1 Build Validation - Full build, classify failures as INFRA/ARM64/PRE-EXISTING
3. 3.2 Functional Testing - Execute test suite, classify failures, determine final build
4. 3.3 Startup Validation - Verify application starts, JVM flags accepted, no crashes
5. Write 00-summary.md - Consolidate exit criteria using template from documentation-standards.md

Exit Criteria

Must Pass

1. Application compiles on ARM64 without errors
2. Native libraries load on ARM64 (or fallbacks function)
3. All MUST UPGRADE dependencies updated to ARM64-compatible versions
4. No ARM64-specific runtime errors
5. Container images build on ARM64 (if containerized)

Test Criteria

6. Test suite executes on ARM64
7. Failures classified: INFRA (non-blocking) / ARM64 (blocking) / PRE-EXISTING (non-blocking)
8. No ARM64-related test failures

Startup Criteria

9. Application starts on ARM64 without crashes
10. JVM flags accepted without errors

Documentation Criteria

11. All files in graviton-validation/ using canonical names from documentation-standards.md

Test Failure Handling

Infrastructure failures (missing DB, Docker, env vars) are non-blocking. Classify and document them, then run the final build without tests:

• Gradle: ./gradlew clean build -x test
• Maven: mvn clean install -DskipTests

ARM64 failures are blocking. Do not skip tests; the failing build is the final build.

User Responsibility (Post-Transformation)

• Performance benchmarking and load testing
• Integration testing with external services
• CI/CD pipeline configuration for ARM64 builds (if skill-config.md defines ci.system, phrase this recommendation in that system's vocabulary; the skill makes no CI changes itself)

Notes

• ARM64 execution environment required for full validation. On x86, static analysis only.
• Multi-module projects require analysis of all submodules and the full transitive dependency tree
• Graviton instances perform best at higher CPU utilization (70%+ recommended for testing)