What type of instance should you test an upgrade on?

• A. The production environment
• B. A local developer machine
• C. An environment closest to production but not production
• D. A sandbox with minimal data

Answer: (C)

Testing an upgrade is most reliable when done in an environment that mirrors production as closely as possible, but is kept separate from live users. This setup lets you exercise migrations, verify plugin and integration compatibility, and observe performance and behavior with data and configurations that resemble what you’ll see in production. If you test in production, a failed upgrade could disrupt users and risk data integrity. Testing on a local developer machine misses critical aspects like real data volume, complex configurations, and integrations, so it won’t reveal many upgrade-time issues. A sandbox with minimal data may catch some basic problems, but it won’t expose issues that only appear with production-scale data or settings. Therefore, the best practice is to use an environment that is as close to production as possible while remaining non-production, so the upgrade can be validated safely and effectively before going live.