Zero-downtime deployment

One of the most important aspects of a mission-critical application that needs frequent updates is the ability to do updates in a fashion that requires no outage at all. We call this a zero-downtime deployment. At all times, the application that is updated must be fully operational.

Popular deployment strategies

There are various ways to achieve this. Some of them are as follows:

• Rolling updates
• Blue-green deployments
• Canary releases

Docker Swarm supports rolling updates out of the box. The other two types of deployments can be achieved with some extra effort from our side.

Rolling updates

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