Learning Docker - Second Edition

Load balancing consideration

In the enterprise deployments of Docker Registry, the load balancer is required to distribute loads across registry clusters. To make load balancer work correctly, we need to consider storage driver, HTTP secret, and Redis cache (if configured) to be same for the cluster of registries. If any of these parameters are different, the registry will have trouble serving the requests.  

For example, the storage driver used for Docker images should be the same across all instances of registry. If a particular mount point is used as a filesystem, it should be accessible and attached to all instances of registries. Similarly, if an S3 or IBM object storage is used, registries should be able to access the same storage resource. ...