Availability overview
- High availability
With high availability, WebSphere eXtreme Scale provides reliable data redundancy and detection of failures.
- Replicas and shards
With eXtreme Scale, an in-memory database or shard can be replicated from one JVM (JVM) to another. A shard represents a partition that is placed on a container. Multiple shards that represent different partitions can exist on a single container. Each partition has an instance that is a primary shard and a configurable number of replica shards. The replica shards are either synchronous or asynchronous. The types and placement of replica shards are determined by eXtreme Scale using a deployment policy, which specifies the minimum and maximum number of synchronous and asynchronous shards.
- Configure zones for replica placement
Zone support allows sophisticated configurations for replica placement across data centers. With this capability, grids of thousands of partitions can be managed using a handful of optional placement rules. A data center can be different floors of a building, different buildings, or even different cities or other distinctions as configured with zone rules.
- Multi-master data grid replication topologies
Using the multi-master asynchronous replication feature, two or more data grids can become exact mirrors of one other. This mirroring is accomplished using asynchronous replication among links connecting the data grids together. Each data grid is hosted in an independent catalog service domain, with its own catalog service, container servers, and a unique name. With the multi-master asynchronous replication feature, you can use links to interconnect a collection of these catalog service domains. Then, you can synchronize the catalog service domains with replication over the links. You can construct almost any topology because you choose how to define links among catalog service domains.
- Distribute transactions
Use Java Message Service (JMS) for distributed transaction changes between different tiers or in environments on mixed platforms.
- Map sets for replication
Replication is enabled by associating BackingMaps with a MapSet.
Related concepts
WebSphere eXtreme Scale overview
Transaction processing overview
Tutorials, examples, and samples
Related information