What breaks: four cloning failures

A clone that EMAILED CUSTOMERS, one still POINTING AT PRODUCTION over a database link, one whose CONCURRENT MANAGERS WOULD NOT START, and one REFRESHED OVER A TEST CYCLE NOBODY HAD FINISHED. THE CLONE THAT EMAILED CUSTOMERS IS THE ONE EVERY EXPERIENCED ADMINISTRATOR HAS SEEN. A training system, a test batch, and real invoices to real addresses. The damage is not technical — it is a client's customers receiving something untrue, and their support desk receiving the calls. Lesson 6's first item, and it is first because it is the only one that leaves the building. THE ONE POINTING AT PRODUCTION IS THE QUIET AND MORE DANGEROUS ONE. A database link that resolved to production still does. Reading is bad and writing is worse: a test that updates through the link corrupts production, from a system whose whole purpose was to protect it. And nobody looks for it, because the clone…

In this module: Module 6 · Cloning

1. 1Why anybody wants a clone
2. 2The clone process, end to end
3. 3Preparing the source without an outage
4. 4Configuring the target
5. 5What a clone does not copyFree preview
6. 6The post-clone checklist
7. 7Cloning between different hosts and versions
8. 8Refreshing rather than cloning
9. 9Making it repeatable
10. 10What breaks: four cloning failures
11. 11Lab briefing · Clone, then find what you missed