CT-4N · Four Nines · 99.99%
Runbookly Certified Containers Specialist
Proves you can keep systems running at the Four Nines level of the Containers: Docker, Compose and Swarm lab: you solved the level in the simulator, then built and repaired real systems in a timed practical exam, without being able to test them.
- Practice
- 4 tasks · 70 %
- Theory
- 20 questions · 30 %
- Duration
- 2 h 30 min + 2 pauses of 10 min
- To pass
- 70 % overall, 60 % in practice
- Results
- 24 hours later
- Valid
- 24 months
The exam: practice first, then theory
70 %
Practice in the simulator
4 tasks in the lab you trained in: systems to build from a brief, or to repair. Some come from the level's exercises with other data, most were written for the exam only and are never published.
During the exam you cannot run the simulation: you build or repair, then submit. After the exam our servers replay each system through its day of traffic and failures, and grade it against its objectives.
30 %
Theory
Questions on production situations and on the concepts of the level, drawn for you among the level's exercises and the certification's own bank.
You pass with 70 % overall and at least 60 % in practice: a certified engineer must make systems hold, not only know the answers.
What to master
Every concept below can be asked, and every exercise of the level becomes a scenario of the exam.
- Services and tasks
- Swarm mode
- Image registries
- Build once, deploy everywhere
- Rolling updates
- Healthchecks
- Overlay networks and the routing mesh
- Automatic rollback
- Swarm secrets
- Environment variables
- Keeping secrets out of images
- Placement constraints
- Volumes
- Managers and quorum