Hades is a high availability (HA) data source. This HA data source contains two other data sources: the main one and the failover one. The HA data source exposes one of them at a time and can automatically switch between them when certain conditions are met. These conditions are highly configurable. By default, when the main data source is overloaded, the failover data source is used. The load of a data base is determined on the basis of the average execution time of some configurable SQL statement that is examined periodically. The HA data source exposes through JMX its state and also operations for manual switching between the two contained data sources in case automatic switching must be suppressed for some reason.
New version 1.1.0 is comming! Better than ever;) New features/bugfixes:
- timeout on statement execution can now be forced (for example, timeout on Oracle's preparedStatement not always works; in Hades 1.1.0 it can be forced),
- connections are always closed after measuring load levels even when weird things happen,
- better logging
- runtime exceptions of enclosed data sources are now handled.