Product overview > Availability overview
Map sets for replication
Replication is enabled by associating BackingMaps with a MapSet.
A MapSet is a collection of maps that are categorized by partition-key. This partition-key is derived from the individual map's key by taking its hash modulo the number of partitions. Thus, if one group of maps within the MapSet has partition-key X, those maps will be stored in a corresponding partition X in the data grid. If another group has partition-key Y, all of the maps will be stored in partition Y, and so on. Also, the data within the maps is replicated based on the policy defined on the MapSet, which is only used for distributed eXtreme Scale topologies (unnecessary for local instances).
See Partitioning for more details.
MapSets are assigned what number of partitions they will have and a replication policy. The MapSet replication configuration simply identifies the number of synchronous and asynchronous replica shards a MapSet should have in addition to the primary shard. For example, if there is to be 1 synchronous and 1 asynchronous replica, all of the BackingMaps assigned to the MapSet will each have a replica shard distributed automatically within the set of available containers for the eXtreme Scale. The replication configuration can also enable clients to read data from synchronously replicated servers. This can spread the load for read requests over additional servers in the eXtreme Scale. Replication only has a programming model impact when preloading the BackingMaps.
For details on the various configuration options, see below:
Parent topic:Availability overview
Replicas and shards
Configure zones for replica placement
Multi-master data grid replication topologies
Enable client-side map replication
Configure distributed deployments