Tanzu GemFire: Post-Upgrade Cleanup of Java 8

Products

• VMware Tanzu Data
• VMware Tanzu Gemfire

Issue/Introduction

How do I safely remove Java 8 components after upgrading a GemFire cluster to Java 17?

Environment

• Product: VMware Tanzu GemFire
• Product Versions: All supported Tanzu GemFire versions upgraded to run on Java 17
• Operating Systems: Linux (RHEL, CentOS, Ubuntu, Debian, SUSE), Windows Server
• Java Runtime: Transitioning from Java 8 to Java 17

Cause

Context:

GemFire does not store bundled JRE/JDK components inside its installed directory. It relies entirely on the host OS environment (JAVA_HOME, system $PATH, and system startup scripts).

Resolution

Checklist:

1. Audit Environment: Ensure JAVA_HOME and startup scripts (start locator, start server) point to JDK 17 and include required --add-opens flags.
2. Remove OS Packages: Purge Java 8 using OS package manager (yum remove java-1.8.0-openjdk* or apt purge openjdk-8-*).
3. Update Alternatives: Run update-alternatives --config java to ensure default binary paths reflect Java 17.
4. Clean Legacy JVM Flags: Remove obsolete Java 8 JVM parameters (e.g., -XX:+UseConcMarkSweepGC) from deployment configuration files.

Additional Information

References:

1. Java Support & Encapsulation Requirements:

• Resource: Tanzu GemFire Java Support Guide

2. System Requirements & Supported Configurations:

• Resource: Tanzu GemFire System Requirements & Supported Configurations

3. Garbage Collection Optimization on Java 17:

• Resource: GemFire Java 17 Preparation and ZGC (Knowledge Base Article 294471)

4. Cluster Upgrade & Maintenance:

• Resource: Upgrading Tanzu GemFire Guide