Understanding Topology

Provides an overview of how to define cluster topology.

The data-fabric software uses node topology to determine the location of replicated copies of data. Node topology describes the locations of nodes in a cluster. You can define the cluster topology by specifying a topology for each node in the cluster. Use topology to group nodes by rack or switch, to provide a hint as to how data should be replicated to protect against data loss or unavailability because of a switch or rack failure.

In a topology, data-fabric distributes container copies optimally among leaf nodes. For example, in a topology such as europe/uk/london/DC2/room4/row22, where row22 contains multiple racks such as row22/rack1, row22/rack2, row22/rack3, and so on, data-fabric tries to ensure that all copies of the container do not end up on the same rack (for example, rack1). By setting each leaf value to correspond to a physical rack, you can ensure that replicated data is distributed across racks to improve fault tolerance.