Communication control determination of storing state based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation
A communication control device includes a determining unit, a request unit, a storage control unit, and a recovery unit. The determining unit determines, based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation, any one of a first operation method of storing state information indicating a state of the data operation and a second operation method of avoiding storing the state information as a method for the data operation. The request unit requests server devices to execute the data operation. The storage control unit stores, when the first operation method is determined, the state information in a storage unit upon execution of the data operation. The recovery unit recovers, when a failure occurs upon the execution of the data operation, from the failure by a recovery method suited to the operation method determined by the determining unit.
1. A communication control device to be connected to a plurality of server devices configured to store therein data in a distributed manner, the communication control device comprising:
a determining unit configured to determine, based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation, any one of a first operation method of storing state information indicating a state of the data operation and a second operation method of avoiding storing the state information as a method for the data operation;
a request unit configured to request the server devices to execute the data operation;
a storage control unit configured to store, when the first operation method is determined, the state information in the storage unit upon execution of the data operation; and
a recovery unit configured to recover, when a failure occurs upon the execution of the data operation, from the failure by a recovery method suited to the operation method determined by the determining unit.
2. The communication control device according to claim 1 , wherein the recovery unit recovers from the failure by using the stored state information when the first operation method is determined, and recovers from the failure without using the state information when the second operation method is determined.
3. The communication control device according to claim 1 , wherein the determining unit determines different operation methods in accordance with whether the table has a primary key.
4. The communication control device according to claim 1 , wherein determining unit determines different operation methods in accordance with a type of a transaction executed by the data operation.
5. The communication control device according to claim 1 , wherein the determining unit determines an operation method that differs depending on a type of the data operation.
6. The communication control device according to claim 1 , wherein, when data to be operated by the data operation is stored in a plurality of tables, the determining unit determines, for each of the tables, an operation method on the basis of the requested data operation and a schema of the table.
7. A communication control method to be executed in a communication control device connected to a plurality of server devices configured to store therein data in a distributed manner, the communication control method comprising:
determining, based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation, any one of a first operation method of storing state information indicating a state of the data operation and a second operation method of avoiding storing the state information as a method for the data operation;
requesting the server devices to execute the data operation;
storing, when the first operation method is determined, the state information in a storage unit upon execution of the data operation; and
recovering, when a failure occurs upon the execution of the data operation, from the failure by a recovery method suited to the operation method determined at the determining.
8. A computer program product having a non-transitory computer readable medium including programmed instructions, wherein the instructions, when executed by a computer connected to a plurality of server devices configured to store therein data in a distributed manner, cause the computer to perform:
determining, based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation, any one of a first operation method of storing state information indicating a state of the data operation and a second operation method of avoiding storing the state information as a method for the data operation;
requesting the server devices to execute the data operation;
storaging, when the first operation method is determined, the state information in a storage unit upon execution of the data operation; and
recovering, when a failure occurs upon the execution of the data operation, from the failure by a recovery method suited to the operation method determined at the determining.
9. A communication system, comprising:
a plurality of server devices configured to store therein data in a distributed manner; and
a communication control device,
the communication control device comprising:
a determining unit configured to determine, based on a requested data operation and a schema of a table that stores therein data to be operated by the data operation, any one of a first operation method of storing state information indicating a state of the data operation and a second operation method of avoiding storing the state information as a method for the data operation;
a request unit configured to request the server devices to execute the data operation;
a storage control unit configured to store, when the first operation method is determined, the state information in a storage unit upon execution of the data operation; and
a recovery unit configured to recover, when a failure occurs upon the execution of the data operation, from the failure by a recovery method suited to the operation method determined by the determining unit,
the server devices each comprising:
a second storage unit configured to store therein the state information;
a judging unit configured to judge whether a state of a data operation requested from the communication control device matches with a state indicated by the state information stored in the second storage unit; and
a data operation unit configured to execute the requested data operation when the judging unit judges that the states match with each other.
10. The communication system according to claim 9 , wherein the server devices each further comprise a verification unit configured to verify whether the schema of the table that stores therein the data to be operated by the data operation, which is transmitted from the communication control device, is proper.
11. The communication system according to claim 9 , wherein when the requested data operation is a data operation for which the first operation method is determined, the judging unit judges whether a state of the requested data operation matches with the state indicated by the state information stored in the second storage unit.