摘要 |
The present invention relates to a method of performing a transaction that affects several nodes within a system of nodes in which information belonging to a distributed database is stored. The transaction is opened with a first phase in which the transaction coordinator sends a "prepare" message (a) to the first node (n1), the first node then sends a request (b) for preparation or an "unprepared" message to the second node (n2) eitehr directly or via one or more intermediate nodes (n3), whereafter the second node sends a "prepared" message or an "unprepared" message (c) directly to the transaction coordinator (1), which concludes the first phase. In a second phase, the transaction coordinator (1) sends to the second node a message (d) regarding measures to be taken and the second node then sends the message (e) regarding measures to be taken to the first node (n1), either directly or via one or more intermediate nodes. The first node then sends a concluding message (f) to the transaction coordinator (1), which concludes the second phase. |