Berkeley DB Java Edition High Availability (JE HA) enables replication of JE environments. JE HA is an embedded database management system designed to provide fast, reliable, and scalable data management. A JE environment is replicated across the nodes of a single read/write Master, multiple read only Replica Replication Group. JE HA is used to improve application availability, provide improved read performance, and increase data durability.

### Getting Started

The Replication Guide is invaluable for understanding the capabilities of JE HA and how best to design your replicated application.

> The Introduction covers terminology, the replication group lifecycle, and the concepts of durability and consistency. Much of the javadoc refers to the topics covered there.

> Replication API First Steps explains how to configure and start a replication group.

> Transaction Management highlights the tradeoffs that must be considered in a replicated application and provides some use cases.

In addition, the je.rep.quote example package provides three example replication applications.

### What the com.sleepycat.je.rep package contains

##### Replication control

- `ReplicatedEnvironment` is the main access point to replication.
- `ReplicationConfig` and `ReplicationMutableConfig` specify attributes of the replication system.

##### Administration

- `ReplicationNode` and `ReplicationGroup` supply administrative views of the replication system.

##### Support

- `StateChangeListener` and `StateChangeEvent` implement a Listener pattern for tracking changes in the replication system.
- `CommitPointConsistencyPolicy`, `TimeConsistencyPolicy` and `NoConsistencyPolicy` let the user control the read only replica's view of the the replicated data.
- `ReplicatedEnviromentStats` provide feedback on system execution.

### Related Packages

- com.sleepycat.je.rep.monitor lets the application track the replication system in order to do tasks such as load balancing and write request routing.
- com.sleepycat.je.rep.util provides command line and programmatic APIs for administering and starting up a replication system.

### Related Documentation

@see Replication Guide @see JE HA Examples