The /spl phi/ accrual failure detector

Abstract

The detection of failures is a fundamental issue for faulttolerance in distributed systems. Recently, many people have come to realize that failure detection ought to be provided as some form of generic service, similar to IP address lookup or time synchronization. However, this has not been successful so far; one of the reasons being the fact that classical failure detectors were not designed to satisfy several application requirements simultaneously.We present a novel abstraction, called accrual failure detectors, that emphasizes flexibility and expressiveness and can serve as a basic building block to implementing failure detectors in distributed systems. Instead of providing information of a binary nature (trust vs. suspect), accrual failure detectors output a suspicion level on a continuous scale. The principal merit of this approach is that it favors a nearly complete decoupling between application requirements and the monitoring of the environment.In this paper, we describe an implementation of such an accrual failure detector, that we call the ϕ failure detector. The particularity of the ϕ failure detector is that it dynamically adjusts to current network conditions the scale on which the suspicion level is expressed. We analyzed the behavior of our ϕ failure detector over an intercontinental communication link over a week. Our experimental results show that ϕ performs equally well as other known adaptive failure detection mechanisms, with an improved flexibility.

Towards a Hybrid Federated Cloud Platform to Efficiently Execute Bioinformatics Workflows

“…A fault tolerance service to check the cloud providers and other services status will be developed and evaluated. We also plan to use an adaptive fault monitoring algorithm, as proposed by [18,30] and [70], which are more adaptable to be used in a large-scale distributed environment. It is also important to include a security service and an SLA service in the federated platform.…”

“…There are extensive studies in the literature on failure detection systems [16,31,45,70]. On the other hand, few systems are designed to scale with a large number of nodes as those found on clouds.…”

Keeping up with storage: Decentralized, write-enabled dynamic geo-replication

“…Each node periodically disseminates its status information to a number of randomlyselected nodes and relays status information received from other nodes. This method is also used to detect and advertise node failures across the cluster [35].…”

Application-Layer Fault-Tolerance Protocols

“…One of the key messages of this book is that it is important to distinguish between porting a code Table 1: Syntactical constructs used in several failure detector protocols. ϕ is the accrual failure detector discussed in (Hayashibara, 2004;Hayashibara et al, 2004). D is the eventually perfect failure detector of (Chandra & Toueg, 1996).…”