Browsing by Author "Liang, D"

Now showing 1 - 5 of 5

A fault-tolerant object service in the OMG's object management architecture
(1998-02-01)
Liang, D
;
Chou, SC
;
Yuan, SM
;
資訊工程學系
;
Department of Computer Science
The object management architecture (OMA) has been recognized as a de facto standard in the development of object services in a distributed computing environment. In a distributed system, the provision for failure-recovery is always a vital design issue. However, the fault-tolerant service has not been extensively considered in the current OMA framework, despite the fact that an increasing number of useful common services and common facilities have been adopted in OMA. In this paper, we propose a fault-tolerance developing environment, called Phoinix, which is compatible to the OMA framework. In Phoinix, object services can be developed with embedded fault-tolerance capability to tolerate both hardware and software failures. The fault-tolerance capability in Phoinix is classified into two levels: restart, and rollback-recovery; when the fault-tolerance capability enhances as the level increases. Currently, Phoinix is ported on Orbix 2.0 and on SunOS 4.2. In this paper, the design and implementation of Phoinix is presented and its performance is evaluated. (C) 1998 Elsevier Science B.V.
A fault-tolerant object service in the OMG's object management architecture
(1998-02-01)
Liang, D
;
Chou, SC
;
Yuan, SM
;
資訊工程學系
;
Department of Computer Science
The object management architecture (OMA) has been recognized as a de facto standard in the development of object services in a distributed computing environment. In a distributed system, the provision for failure-recovery is always a vital design issue. However, the fault-tolerant service has not been extensively considered in the current OMA framework, despite the fact that an increasing number of useful common services and common facilities have been adopted in OMA. In this paper, we propose a fault-tolerance developing environment, called Phoinix, which is compatible to the OMA framework. In Phoinix, object services can be developed with embedded fault-tolerance capability to tolerate both hardware and software failures. The fault-tolerance capability in Phoinix is classified into two levels: restart, and rollback-recovery; when the fault-tolerance capability enhances as the level increases. Currently, Phoinix is ported on Orbix 2.0 and on SunOS 4.2. In this paper, the design and implementation of Phoinix is presented and its performance is evaluated. (C) 1998 Elsevier Science B.V.
A fault-tolerant object service on CORBA
(1999-11-01)
Liang, D
;
Fang, CL
;
Yuan, SM
;
Chen, C
;
Jan, GE
The Common Object Request Broker Architecture (CORBA), is a major industrial standard for distributed object-based applications. Today's large-scale CORBA applications have to deal with object crashes, node failures, networks partitioning and unpredictable communication delays. Existing efforts to enhance the CORBA reliability can be roughly categorized into three approaches: integration approach, interception approach and service approach. Each approach has its own merits and prices. In this paper, we propose a service approach solution called Object Fault-tolerance Service (OFS). Solutions that adopt the service approach usually specify their service in terms of CORBA IDL interfaces. The implementations of such solutions in general do not modify the ORE infrastructure or IDL language mappings, and thus applications developed with those systems appear to be more portable. OFS differs from other service approach solutions in that OFS does not assume underlying support of reliable group communication. Applications with advance registration can rely on OFS for detection of object and node crashes, and for customized recovery. In this paper, we first present the service specification of OFS. We then give the system architecture of an OFS implementation. This OFS implementation is developed on the Solaris 2.5 platform and with IONA's Orbix 2.0. The performance evaluation of the OFS implementation is also presented. The preliminary experiments indicate that OFS overhead is minimal and client objects experience little response delay when a service object is under OFS surveillance. (C) 1999 Elsevier Science Inc. All rights reserved.
Nested transaction and concurrency control services on CORBA
(1997)
Liang, KC
;
Yuan, SM
;
Liang, D
;
Lo, W
;
交大名義發表
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.
The design and implementation of a multi-threaded object request broker
(2000-05-01)
Lo, W
;
Chang, YS
;
Yuan, SM
;
Liang, D
;
資訊工程學系
Multi-threaded programming is a well-known technique for improving the performance of applications. In a CORBA environment, clients can invoke shared remote objects. If these objects are single-threaded, the performance of the system in the large distributed applications is affected. This paper presents a detailed description of the design and implementation of a multi-threaded Object Request Broker (ORB) on CORBA. The ORE was implemented on top of Windows NT and the underlying TCP protocol. The system's performance in both one-way and two-way requests is compared with that of a well-known commercial product, the IONA Orbix.