This section explains the procedure for performing system switchover when an RDAREA input/output error (path error) has occurred. For this purpose, an I/O error means an error that occurs when HiRDB manipulates a file, when HiRDB can no longer distinguish a file, when file manipulation fails. The error code returned from the request for access to the HiRDB file system is -1544.
If unitdown is specified in the pd_db_io_error_action operand, HiRDB (or unit in the case of a HiRDB/Parallel Server) terminates abnormally when an RDAREA I/O error occurs and system switchover is performed. When the cause of the I/O error is a path error, job tasks can continue because I/O processing can be performed after system switchover is performed. For this purpose, a path error means a status in which files cannot be accessed because the path of communication between HiRDB and the files was interrupted.
For details about specifying unitdown in the pd_db_io_error_action operand, see 18.20 Actions to take when an RDAREA I/O error occurs.
If system switchover is to be performed when HiRDB terminates abnormally, specify pd_mode_conf=MANUAL2. If system switchover is not to be performed (if HiRDB is to restarted on the abnormally terminated system), specify pd_mode_conf=MANUAL1.
Specify switch in the switchtype operand for HA monitor or Hitachi HA Toolkit Extension. When switch is specified, system switchover will be performed when HiRDB terminates abnormally.
When in the monitor mode, a system cannot be switched automatically even if HiRDB terminates abnormally. Systems can be switched only by a user operation (such as by executing a system switchover shell script). Example system switchover operations are explained below.
When an I/O error occurs and HiRDB terminates abnormally, perform a system switchover and continue the processing in progress when the error occurred. Also, read the output messages and resolve the error. Then, either perform another system switchover or terminate and restart HiRDB, as appropriate. If the I/O error recurs after the system switchover, the RDAREA is shut down. In such a case, use the database recovery utility (pdrstr command) to recover the RDAREA.