When the Feature Session Persistence is enabled, there can only be one active/providing service Drools PDP due to the behavior of Drools persistence. The Active/Standby Management Feature controls the selection of the Drools PDP that is providing service. It utilizes its own database and the State Management Feature database in the election algorithm. All Drools PDP nodes periodically run the election algorithm and, since they all use the same data, all nodes come to the same conclusion with the "elected" node assuming an active/providingservice state. Thus, the algorithm is distributed and has no single point of failure - assuming the database is configured for high availability.
When the algorithm selects a Drools PDP to be active/providing service the controllers and topic endpoints are unlocked and allowed to process transactions. When a Drools PDP transitions to a hotstandby or coldstandby state, the controllers and topic endpoints are locked, preventing the Drools PDP from handling transactions.
When the Feature Session Persistence is enabled, there can only be one active/providing service Drools PDP due to the behavior of Drools persistence. The Active/Standby Management Feature controls the selection of the Drools PDP that is providing service. It utilizes its own database and the State Management Feature database in the election algorithm. All Drools PDP nodes periodically run the election algorithm and, since they all use the same data, all nodes come to the same conclusion with the "elected" node assuming an active/providingservice state. Thus, the algorithm is distributed and has no single point of failure - assuming the database is configured for high availability.
When the algorithm selects a Drools PDP to be active/providing service the controllers and topic endpoints are unlocked and allowed to process transactions. When a Drools PDP transitions to a hotstandby or coldstandby state, the controllers and topic endpoints are locked, preventing the Drools PDP from handling transactions.