Cost-based transaction coordinator algorithm implemented at persistent distributed shared virtual memory

In order to support processing of highly concurrent transactions at low price on distributed database server systems, a network of workstations (NOW) is used as the hardware environment. In order to share resources that are distributed among different sites of NOW and support the database functionalities, persistent distributed shared virtual memory (PDSVM) is implemented on ShusseUo, an object database system developed by Kyushu University, Japan. In ShusseUo, all workstations cooperate to perform jobs submitted by database applications. Each job consists of several transactions. These transactions are executed on PDSVM and the cost of each transaction varies according to the workstation on which the transaction runs. We present the cost-based transaction coordinator (CTC) algorithm. In CTC, the load information of a transaction is collected automatically while the transaction is running, and it is fed back when the transaction is committed. In CTC, each transaction is coordinated to a certain workstation based on its cost as calculated using the fed back information and the distribution information of the database. The algorithm is evaluated in terms of the TPC-C benchmark. The benchmark result is presented and analyzed.