DTCOT: distributed timeout based transaction commit protocol for mobile database systems

Advancements in communication technologies have given rise to Mobile Database Systems (MDS). MDS allows a mobile user to initiate transactions from anywhere and at any time and guarantees their consistency preserving execution. Transaction processing in MDS has been suggested by modifying the traditional two and three phase commit (2PC) to accommodate the limitations of a Mobile Host and wireless network like intermitted connectivity, limited power, limited memory etc. A timeout based approach "Transaction Commit on Timeout", TCOT, has been suggested which shows better performance compared to 2PC and 3PC. However, this scheme does not explicitly consider a distributed database system. We propose a scheme Distributed Transaction Commit on Timeout, DTCOT, to commit the transaction in a MDS environment with distributed database. This scheme uses a timeout to decide a commit or abort. DTCOT requires two coordinators: - one for coordinating the entire transaction execution and one, which acts as the interface to the distributed database (i.e. database coordinator). The database coordinator is required because data distribution must be transparent the end user (i.e. transaction coordinator). This is a one-phase protocol due to which the time and message complexity are much lower compared to the conventional 2 phases commit and 3 phase commit protocols. We will compare the performance with the modified 2PC and show that it performs better w.r.t. Message and time complexity.