Glossary · Automation software engineering and architecture
Blue-green deployment
Also known as: Blue/green deployment
German: Blue-Green-Bereitstellung
In software engineering, blue-green deployment is a release technique in which two identical production environments exist: one (blue) serves users while the new version is installed and tested on the other (green), and traffic is then switched to green, with blue kept available for a fast rollback.
- Software engineering
In one sentence
Blue-green deployment runs two identical environments and switches traffic to the updated one, keeping the old one ready for rollback.
Example
An MES application is updated on the standby server cluster; after smoke tests, the load balancer switches the line clients to it, and the old cluster stays ready for rollback.
How it applies
- Engineering: Blue-green deployment needs two complete environments and a switch point, such as a load balancer, DNS entry or container orchestration rule. It is common for IT-level and edge applications, less so for PLC programs running on a single controller.
- Operation: The switch is fast, and rolling back means switching back. Data migrations are the hard part: both versions must be able to work with the data during the transition.
- Documentation: Operating procedures should describe the switch, the checks before and after it, the rollback criteria and who decides. Record which environment is live at any time, so incident analysis can match logs to the right version.
Blue-green vs. canary deployment
Blue-green switches all traffic at once. Canary deployment moves a small share of traffic or a few sites to the new version first and increases it gradually. Canary releases limit the blast radius of a defect; blue-green offers a simpler, all-or-nothing switch with instant Rollback capability.