Ha-jdbc is a jdbc proxy that provides light-weight, transparent, fault tolerant clustering capability to any underlying jdbc driver.

features include:

* supports any database accessible via jdbc.
* high-availability/fault tolerance - an ha-jdbc database cluster can lose a
node without failing/corrupting open transactions.
* live activation/deactivation allows for maintenance/upgrading of a database
node without loss of service.
* improves performance of concurrent read-access by distributing load across
individual nodes.
* supports full jdbc 3.0 and 4.0 feature set.
* out-of-the-box database-independent strategies for synchronizing a failed
cluster node.
* exposes jmx management interface to allow administration of databases and
clusters.
* ability to add/subtract database nodes to/from a cluster at runtime.
* can be configured to auto-activate failed database nodes during scheduled
off-peak times.