Recording medium storing update processing program for storage system, update processing method, and storage system

An update processing method for a storage system that stores data distributedly in a plurality of storage devices, the method comprising:

• a procedure in which a process control unit, which controls operations of a process that executes a specific service processing and a new process, issues an instruction to accumulate write data written in the storage devices while the process is executing the specific service processing and to switch a reading and writing unit operation mode, which selects an asynchronous mode that writes the accumulated data into the storage devices at a specific timing, to a synchronous mode that writes the write data directly into the storage devices, when an update is requested;
• a procedure in which a synchronization and asynchronization instructing unit issues, according to the instruction of the process control unit, an instruction for switching the asynchronous mode to the synchronous mode to the reading and writing control unit that writes, in the storage device, the write data output by the process or the new process in the synchronous mode or the asynchronous mode;
• a procedure in which the process control unit issues an end instruction to the process and causes the process to end the service processing in a state in which the reading and writing control unit operates in the synchronous mode and the write data of the process is directly written in the storage devices;
• and
• a procedure in which the process control unit starts service processing of the new process after the process ends the service processing.

A storage system that stores data distributedly among a plurality of storage devices, the system comprising:

• a storage node including:
• a reading and writing control unit which has a synchronous mode for directly writing write data in the storage devices and an asynchronous mode for accumulating the write data in a cache memory and writing the accumulated data in the storage devices at a specific timing, when a request to write data to the storage devices is received;
• a synchronization and asynchronization instructing unit that instructs whether data writing is to be performed in the synchronous mode or in the asynchronous mode;
• a process control unit that performs processing for controlling an operation of a process that is executing specific service processing and a new process, for instructing, according to an input instruction, the synchronization and asynchronization instructing unit to switch the reading and writing control unit, which is set in the asynchronous mode while the process is executing the service processing, to the synchronous mode, processing for issuing an end instruction to the process to cause the process to end the specific service processing in a state in which the write data output by the process is directly written in the storage device, and processing for starting service processing of the new process after the process ends the specific service processing and notifies an end result every time the processing ends;
• and
• a management node including:
• a management information storing unit that is connected to the plurality of the storage nodes via a network and stores update management information concerning a progress state of an update of the storage node having the process as an update target;
• and
• an update managing unit that instructs, based on the update management information stored in the management information storing unit, all the storage nodes to switch to the synchronous node, instructs the storage nodes to stop the process when all the processing of the storage nodes is successful, and causes the storage nodes to start the new process and start a service by the new process when the processing of the storage nodes is successful.