Patchmageddon articles https://patchmageddon.com JVM discovery, patching and OpenJDK migration for enterprise Java estates. en Oracle JDK 21's free update window has closed. Here's what that means. https://patchmageddon.com/articles/java-21-nftc-free-period-ended https://patchmageddon.com/articles/java-21-nftc-free-period-ended Oracle JDK 21 updates released after September 2026 are no longer free for production use. Your options: pay, stop patching, or migrate to OpenJDK. Tue, 22 Sep 2026 00:00:00 GMT Oracle Java Licensing How Oracle's employee-based Java metric works, and why a few installs can price your whole company https://patchmageddon.com/articles/oracle-java-employee-metric-explained https://patchmageddon.com/articles/oracle-java-employee-metric-explained Oracle's Java SE Universal Subscription is priced per employee, not per install. How the metric works, a worked example, and why your inventory drives the cost. Tue, 15 Sep 2026 00:00:00 GMT Oracle Java Licensing Oracle JDK to OpenJDK: a practical migration checklist https://patchmageddon.com/articles/oracle-jdk-to-openjdk-migration-checklist https://patchmageddon.com/articles/oracle-jdk-to-openjdk-migration-checklist A step-by-step checklist for moving from Oracle JDK to an OpenJDK build: choosing a distribution, what differs between vendors, verification and cleanup. Tue, 08 Sep 2026 00:00:00 GMT OpenJDK Migration You can't patch what you can't find: building a real JVM inventory https://patchmageddon.com/articles/finding-every-jvm-in-your-estate https://patchmageddon.com/articles/finding-every-jvm-in-your-estate Most enterprises can't say how many JVMs they run or where. Here's what a useful JVM inventory captures, how to collect it, and where it goes wrong. Tue, 01 Sep 2026 00:00:00 GMT JVM Discovery & Inventory How to get your CAB to approve faster JVM patching https://patchmageddon.com/articles/cab-approval-for-faster-jvm-patching https://patchmageddon.com/articles/cab-approval-for-faster-jvm-patching Faster JVM patching is mostly a governance problem. How to score criticality, set thresholds and build the evidence a Change Advisory Board can approve. Tue, 25 Aug 2026 00:00:00 GMT Risk & Governance Fast detection and rollback: a safer alternative to full regression testing https://patchmageddon.com/articles/fast-detection-and-rollback-instead-of-regression-testing https://patchmageddon.com/articles/fast-detection-and-rollback-instead-of-regression-testing For low-criticality apps, quick detection and cheap rollback cut JVM patch risk more than a full regression run. Here's how to build that safety net. Tue, 18 Aug 2026 00:00:00 GMT Patch Management Six ways JVM changes break production, and how to see them coming https://patchmageddon.com/articles/jvm-patch-failure-modes https://patchmageddon.com/articles/jvm-patch-failure-modes APM agents, TLS defaults, JIT warm-up, GC changes, removed APIs and container awareness: how each JVM failure mode shows up, and how to catch it before rollout. Tue, 11 Aug 2026 00:00:00 GMT Patch Management Patching the JVMs you didn't install: Java inside vendor products https://patchmageddon.com/articles/patching-jvms-inside-vendor-products https://patchmageddon.com/articles/patching-jvms-inside-vendor-products Many commercial products ship their own Java runtime. Why scanners miss them, what vendors will support, and how to handle the ones you can't patch yourself. Tue, 04 Aug 2026 00:00:00 GMT Vendor & Third-Party Apps