An implementation and performance measurement of the progressive retry technique

This paper describes a recovery technique called progressive retry for bypassing software faults in message-passing applications. The technique is implemented as reusable modules to provide application-level software fault tolerance. The paper describes the implementation of the technique and presents results from the application of progressive retry to two telecommunications systems. the results presented show that the technique is helpful in reducing the total recovery time for message-passing applications

Minimizing Completion Time of a Program by Checkpointing and Abstract

Checkpointing with rollback-recovery is a well known technique to reduce the completion time of a pro-gram in the presence of failures. While checkpointing is corrective in nature, rejuvenation refers to preventive maintenance of software aimed to reduce unexpected failures mostly resulting from the “aging ” phenomenon. In this paper, we show how both these techniques may be used together to further reduce the expected comple-tion time of a program. The idea of using checkpoints to reduce the amount of rollback upon a failure is taken *Supported in part by an IBM fellowship and by an AT&T Bell laboratories summer internshi

Design Strategies

With the explosive growth of the World Wide Web, some popular Web sites are getting thousands of hits per second. As a result, clients (browsers) experience slow response times and sometimes may not be able to access some Web sites at all. Upgrading the server nodes to more powerful machines may not always be cost-effective. A natural solution is to deploy a set of machines, or a cluster, and have them work together to host a single service. Such a server cluster should preferably publicize only one server name for the entire cluster so that any configuration change inside the cluster does not affect client applications. In this paper, we first discuss existing approaches to distributing client's requests for a single service to different machines in a cluster. We then propose two new techniques, collectively called ONE-IP, based on dispatching packets at the IP level. They have the advantages of fast dispatching and ease of implementation. Ideas presented here are generic and should be applicable to other services as well

Descriptional Complexity of Machines with Limited Resources

Over the last 30 years or so many results have appeared on the descriptional complexity of machines with limited resources. Since these results have appeared in a variety of different contexts, o rgo4 here is to pro vide a survey o these results. Particular emphasis is put o limiting reso rces (e.g., no ndeterminism, ambiguity,lo o ahead, etc.) fo vario s types o finite state machines, pushdo wn auto mata, parsers and cellular auto mata ando n the e#ect it haso n their descriptio nal co mplexity. We also address the questio no f how descriptional complexity might help in the future to solve practical issues, such as software reliability