NONBLOCKING 2-PHASE COMMIT PROTOCOL TO AVOID UNNECESSARY TRANSACTION ABORT FOR DISTRIBUTED SYSTEMS

Processing a distributed transaction takes more time than processing a local transaction, since processing of a distributed transaction requ ires multiple phases with respect to its commitment to keep a distribu ted transaction consistent. For distributed systems, since the commit cost could be high due to volume of network messages and network delay s, it is required to optimise commit protocol to improve transaction t hroughput. In order to improve the throughput of transaction processin g, we concentrate on the nonblocking property without loss of consiste ncy, including the number of message exchanges, recovery time. Blockin g is a critical problem in transaction processing with respect to thro ughput, since blocked transactions interfere the progress of other tra nsactions. Abortion of the commitable transaction makes the system deg rade, and it becomes serious if there are many transactions at the fai led sites due to the unnecessary restart overhead. Therefore, in the v iew of efficiency, it is essentially required to develop a commit prot ocol that has not only few message exchanges but also low ratio of tra nsaction aborts.