Patent ID: 8185493
Filing Date: 2012-05-22
Classification: G06F

Abstract:
1. A solution method of an in-doubt state in two-phase commit protocol of a distributed transaction, comprising: assigning a unique identifier to each of a plurality of log groups, and registering information about a database management device having the management right of each of the log groups in a first table, wherein a log group is a package of a data storage device storing data and a log storage device storing a log of the data; storing, in a first preparation completion log outputted to a log storage device of a global representative log group representing log groups managed by a database management device which is a coordinator in a two-phase commit of a distributed transaction in which the plurality of log groups participate, a list of identifiers of log groups managed by a database management device which is a participant of the distributed transaction; storing an identifier of the global representative log group in a second preparation completion log, the second preparation completion log being outputted to a log storage device of a log group managed by a database management device which is a participant in the two-phase commit; in response to a moving of the management right of the global representative log group to another database management device during an in-doubt state period of the two-phase commit, rewriting the first table to reflect moving of the management right of the global representative log group; in response to a moving of the management right of a log group other than the global representative log group to another database management device during the in-doubt state period of the two-phase commit, rewriting the first table to reflect moving of the management right of a log group other than the global representative log group; wherein a participant in an in-doubt state referring to an identifier of the global representative log group stored in the second preparation completion log and the first table and inquiring about a transaction result of a database management device having a management right of the global representative log group; and the coordinator referring to a list of identifiers log groups stored in the first preparation completion log and the first table and returning a transaction result to a participant in response to receiving an inquiry about the transaction result from the participant in the in-doubt state.