Showing papers by "Shyan-Ming Yuan published in 1997"
27 May 1997
TL;DR: This work proposes a "warm stand-by" replication approach that defines four interfaces and provides class implementations that can help programmers write programs with fault-tolerant capability.
Abstract: There are more and more COSS (Common Object Service Specifications) on CORBA (Common Object Request Broker Architecture) announced by the OMG (Object Management Group), but no common specification about fault-tolerance exists. We propose a "warm stand-by" replication approach. When an object (primary object) is invoked, it will invoke a secondary object, and the primary object will log the messages and checkpoint the state to the secondary object periodically. If the primary object fails, the secondary object can take over by way of a client executing a few operations to change the secondary object's mode to primary. Following the style of COSS, we define four interfaces and provide class implementations that can help programmers write programs with fault-tolerant capability. The whole model has been implemented on Orbix, which is a full implementation of CORBA specification.
43 citations
15 Dec 1997
TL;DR: A new quorum-based replica control protocol whose quorum size is O(/spl radic//N), which is the same as that of the grid protocol, and which performs well in systems where read operations are requested more frequently than write ones.
Abstract: Data replication is an important issue in distributed systems. Many protocols are designed to achieve high availability, but some of them have restrictions on N, the number of nodes in the system. This motivates us to design a protocol suitable for arbitrary N. In this paper, we present a new quorum-based replica control protocol whose quorum size is O(/spl radic//N), which is the same as that of the grid protocol. Moreover; the proposed protocol is almost symmetric, i.e., each node nearly bears the same responsibility. In particular, our protocol performs well in systems where read operations are requested more frequently than write ones.
14 citations
11 Aug 1997
TL;DR: The paper presents an implementation of the Object Transaction Service (OTS) based on CORBA 2.0 specification, and preliminary results obtained from the experiments on Sun workstations with Orbix 1.3 show that the overhead due to the OTS service is satisfactory for most applications.
Abstract: The concept of transactions is not only indispensable in database applications, but also useful in building robust software for mission critical applications. The paper presents an implementation of the Object Transaction Service (OTS) based on CORBA 2.0 specification. Transactional applications developed with the support of our OTS implementation are able to assure the ACID properties even in the presence of node crashes, software system failures and process hangs. The preliminary results obtained from the experiments on Sun workstations with Orbix 1.3 show that the overhead due to the OTS service is satisfactory for most applications.
8 citations
Journal Article•
5 citations
29 Oct 1997
TL;DR: The motivations, the issues and the design of translating RPC services into CORBA objects via reengineering processes are identified and the conversion includes: converting RPC languages to CORBA IDL (Interface Definition Language), converting RPC server implementation source codes to CorBA server object implementation source code, and converting RPC clients' source codesto CORBA client object source code.
Abstract: The remote procedure call (RPC) paradigm has successfully modeled several sophisticated client-server applications. It provides a simple and efficient way to develop distributed programs. The concept of RPC comes from procedure-based programming languages. As object-oriented technologies grow, the idea of invoking program entities on different address spaces also comes into object-oriented software development. Distributed object computing is the realization of this trend. This paper identifies the motivations, the issues and the design of translating RPC services into CORBA objects via reengineering processes. The conversion includes: converting RPC languages to CORBA IDL (Interface Definition Language), converting RPC server implementation source codes to CORBA server object implementation source code, and converting RPC clients' source codes to CORBA client object source code.
5 citations
30 May 1997
TL;DR: In this article, the authors present the exploration and integration of the object transaction service and concurrency control service based on CORBA and provide not only the flat transaction model but also the nested transaction model.
Abstract: This paper presents the exploration and integration of the object transaction service and concurrency control service based on CORBA. We provide not only the flat transaction model but also the nested transaction model. Nested transaction provides isolation of failures and enhances concurrency of long-lived transaction. Issues on supporting nested transactions in both the object transaction service and the concurrency control service are discussed. We also reveal the necessary overhead introduced by these two services in our implementation.
5 citations
11 Aug 1997
TL;DR: The concept of the two-level agent is introduced, and practical issues involved in further design are investigated, to try to solve problems frustrate WWW users.
Abstract: Many problems frustrate WWW users, who suffer limited accessibility to WWW resources, and so the authors propose a two-level agent architecture to try to solve them. The agent consists of two parts: the local agent interacts directly with end-users, while the remote agent interacts primarily with the public Internet. Together they learn user preferences, and help users find and filter information more efficiently, economically, and enjoyably. The paper introduces the concept of the two-level agent, and investigates practical issues involved in further design.
1 citations