A Variable Cache Consistency Protocol for Mobile Systems Using Time Locks

Abstract. By locally caching data, mobile hosts can operate while disconnected from the central server, however, consistency of data becomes more difficult to maintain. In this paper we propose a protocol that makes a distinction between two classes of consistency: weak and strict, and treats them differently. Strict consistency is used for data that needs to be consistent all the time, whereas weak consistency is for cases when stale data can be tolerated in the form of requiring only specific updates. Consistency is maintained by using strict read/write and permissive read/write time locks that enable data sharing for a fixed time period and support concurrency control. A Notification Protocol is also proposed, which enables propagating updates to clients and retrieving data from clients in a consistent manner. Performance tests have demonstrated that switching from strict to weak consistency can reduce the number of aborts (due to no access to a lock or conflicting operations) ...

• Type: Conference
• Year: 2003
• Where: DAIS
• Authors: Abhinav Vora, Zahir Tari, Peter Bertók
• Keywords: Consistency, DAIS 2003, DAIS 2007, Strict Consistency, Weak Consistency