Transactional workflow paradigm

Abstract

This paper proposes a workflow paradigm for mobile computing environment to support long duration computations with a specific control flow and short duration transactions. This paradigm combines the ConTract Model of Wachter and Reuter and the negotiation model proposed by Puustjarvi; it can provide for recovery of long-lived activites satisfying specific control flow, consistency control, conflict resolution and compensation through an intention-action protocol. Also issues related relaxing the ACID, local and global serializability properties of transactions, and mobile-host dependencies are considered. Also we mention the application of agent -based workflow, PJava and JDBC tools. Relevant bibliography is included.

Integrated network computing models, programming modes and software tools

“…Isolation -that is intermediate results are not externally made visible until commitment Durability -that is the effects are made permanent when a transaction succeeds and recovers under failure. The ACID properties turn out to be restrictive for a mobile environment and need to be relaxed, see [24].…”

“…This can be specified by condition -event-action or rule based systems ( or equivalently by scripts, protocols defined as a well-formed sentence in a formal grammar) Thus in a mobile environment,the traditional transaction model needs to be replaced by a more realistic model in which the isolation property is removed and intermediate results are visible and precedence order in execution and other dependencies are taken care of therby removing the atomicity restrictions. Such a model turns out to be a workflow model between the MH and FH supported by suitable protocols.Details of this model are avilable in [24]. We provide a brief summary here.…”

Mobile computing: operational models, programming modes and software tools

“…This would require the analysis as to how the respective internal and external transactions interfere with each other when they are applied. In order to execute the internal transactions concurrently they must satisfy the following conditions [18][19][20][21][22][23][24][25]: 1.The set of objects in each FH(p) and in each MH(i) accessed by any two different intran are pairwise-disjoint. 2.…”

“…Although such fixed-wired networks provide very reliable communication, they restrict the application of distributed heterogeneous computing to an immobile, rigid communication structure. In order to provide mobile computing services we need to interconnect the computers through an integrated wired and wireless network of computers [3], [6], [9], [24], [29]. With the availability of powerful computing devices of the size of our palm (like the HP-100 palmtop and wireless handheld computers called personal digital assistants (PDA), e.g., Apple Newton) in both home and office, the demand for the development of an integrated wired and wireless networking environment (called mobile environment) of these computers is growing rapidly.…”

“…The mobile computing environment [3] , [6], [9], [24], [29] consists of fixed host computers and mobile client computers. Fixed hosts (FH) are connected together via a fixed high speed network (Mbps to Gbps).…”