When a front-end server unit terminates abnormally, any transaction that was being executed from this front-end server might end up in uncompleted status. A transaction that is thrown into uncompleted status might still be maintaining a lock on the database, thus preventing other transactions from referencing or updating the database. Ordinarily, a transaction in uncompleted status must be completed from the front-end server, so you must first recover the front-end server unit from the error and then restart the unit.

When a recovery-unnecessary front-end server is used, a transaction in uncompleted status is completed automatically when the front-end server unit terminates abnormally (the transaction is completed without waiting for the front-end server to restart). You can install a front-end server unit in an application server that does not use system switchover, and use reduced operation for the front-end server unit.

Whereas normally the pdrplstart and pdrplstop commands can be executed only when all units and servers are running, use of a recovery-unnecessary front-end server means that these commands will execute even though a recovery-unnecessary front-end server or recovery-unnecessary unit is stopped.

For details about recovery-unnecessary front-end servers, see the HiRDB Version 9 Installation and Design Guide.

To use a recovery-unnecessary front-end server, HiRDB Non Recover FES must be installed.