Chapter 13. Orchestrating services on a cluster of Docker hosts with Swarm
This chapter covers
- How Docker application deployments work and options
- Deploying a multitier application to Docker Swarm
- How Swarm attempts to converge the Docker application deployment to the desired state declared by operators
- How Swarm ensures the desired number of replicas are running around the cluster within the declared placement and resource constraints
- Routing of request traffic from a cluster node to network service instances and how collaborating services reach each other using Docker networks
- Controlling placement of Docker Service containers within the cluster
Application developers and operators frequently deploy services onto multiple hosts to achieve greater availability and scalability. When an application is deployed across multiple hosts, the redundancy in the application’s deployment provides capacity that can serve requests when a host fails or is removed from service. Deploying across multiple hosts also permits the application to use more compute resources than any single host can provide.