MySQL Version Migration: Understanding BOSH Lifecycle and Instance Upgrades

Products

• VMware Tanzu Platform - Cloud Foundry
• VMware Tanzu for MySQL
• VMware Tanzu Platform Data

Issue/Introduction

Customers upgrading VMware Tanzu for MySQL from version 8.0 to 8.4 (LTS) may have concerns about whether infrastructure-level maintenance—such as stemcell rolls, bosh recreate, or BOSH sidecar activities—will inadvertently force a major version database upgrade or change instance types before applications are ready.

Cause

Major database version jumps (e.g., 8.0 to 8.4) are disruptive and are governed by the Service Broker and Tile lifecycle errands, rather than standard BOSH infrastructure updates. Understanding the boundaries between the Stemcell (OS) and the Service Instance (Database) is critical for a phased migration.

Resolution

Infrastructure maintenance activities do not trigger major version upgrades. The upgrade of a MySQL service instance only occurs under specific conditions:

 

1. Controlled Upgrade Triggers

An instance upgrade will only be initiated if:

• The Upgrade All Service Instances errand is executed via Ops Manager.
• A user manually triggers an upgrade via the CLI using: cf update-service SERVICE_INSTANCE.

 

Other activities, including stemcell rolls, BOSH recreations, and standard BOSH sidecar updates, will replace the underlying VM but will not attempt to upgrade the database version or change the instance type/plan.

 

2. Recommended Phased Migration Strategy

To safely upgrade the tile while protecting production environments:

• Disable Errands: You can safely upgrade the MySQL tile in Ops Manager by ensuring the Upgrade All Service Instances errand is disabled.
• Individual Validation: Allow users to manually upgrade specific instances in development environments using cf update-service` to perform testing and validate application compatibility with MySQL 8.4.
• Verify Health: Ensure no orphaned service instances exist before attempting broad upgrades, as these can block the lifecycle errands Orphaned MySQL Instances.

 

3. Troubleshooting Version Mismatches

If an upgrade is accidentally attempted and fails, or if a bosh recreate is performed on a failing VM, you may encounter InnoDB corruption errors (e.g., Table flags are 0). This typically indicates a version mismatch where a newer data directory is being accessed by an older binary.

 

Refer to MySQL Startup Failures for steps to verify the data directory state and Stemcell Upgrade Failures to resolve issues where service instances remain on old infrastructure following a tile update.