Lightbits SDS Cluster Multi AZ

Lightbits SDS can be deployed in a MultiAZ topology. This means that the cluster will be deployed over three availability zones in the region in order to achieve maximum data durability. It is recommended to work in Azure with volumes that have three replicas. In a MultiAZ deployment, each AZ will hold one replica of the data. This enables the cluster to overcome failures in a particular availability zone. The cluster is split into three main failure domains - one for each AZ.

When deploying a MultiAZ cluster, the number of servers in the cluster must divide evenly into three, so that it can balance the nodes evenly between the AZs. The cluster can have 3, 6, 9, 12, or 15 servers in the cluster.

It is recommended to have the volumes that are being used by clients in AZ1 to have volume placement for AZ1. This way the primary replica of the volume will be in the same AZ as the client. This will reduce both the cost of intra-AZ traffic and reduce the latency of the traffic between the clients and the cluster.

In the case of an AZ failure, the primary will automatically fail over to be in one of the other AZs. Once the failed AZ is back to normal, the primary will fail back to the original AZ.