This thesis presents the results of an investigation into the failure detection problem. We consider the specific case of the Quality of Service (QoS) of crash failure detection. In contrast to previous work, we address the crash failure detection problem when the monitored target is resilient and recovers after failure. To the best of our knowledge, this is the first work to provide an analysis of crash-recovery failure detection from the QoS perspective. We develop a probabilistic model of the behavior of a crash-recovery target, i.e. one which has the ability to recover from the crash state. We show that the fail-free run and the crash-stop run are special cases of the crash-recovery run with mean time to failure (MTTF) approaching to infinity and mean time to recovery (MTTR) approaching to infinity, respectively. We extend the previously published QoS metrics to allow the measurement of the recovery speed, and the definition of the completeness property of a failure detector. Then, the impact of the dependability of the crash-recovery target on the QoS bounds for such a crash-recovery failure detector is analyzed using general dependability metrics, such as MTTF and MTTR, based on an approximate probabilistic model of the two-process failure detection system. Then according to our approximate model, we show how to estimate the failure detector’s parameters to achieve a required QoS, based on Chen et al.’s NFD-S algorithm analytically, and how to execute the configuration procedure of this crash-recovery failure detector. In order to make the failure detector adaptive to the target’s crash-recovery behavior and enable the autonomy of the monitoring procedure, we propose two types of recovery detection protocols. One is a reliable recovery detection protocol, which can guarantee to detect each occurring failure and recovery by adopting persistent storage. The other is a lightweight recovery detection protocol, which does not guarantee to detect every failure and recovery but which reduces the system overhead. Both of these recovery detection protocols improve the completeness without reducing the other QoS aspects of a failure detector. In addition, we also demonstrate how to estimate the inputs, such as the dependability metrics, using the failure detector itself. In order to evaluate our analytical work, we simulate the following failure detection algorithms: the simple heartbeat timeout algorithm, the NFD-S algorithm and the NFDS algorithm with the lightweight recovery detection protocol, for various values of MTTF and MTTR. The simulation results show that the dependability of a recoverable monitored target could have significant impact on the QoS of such a failure detector. This conforms well to our models and analysis. We show that in the case of reasonable long MTTF, the NFD-S algorithm with the lightweight recovery detection protocol exhibits better QoS than the NFD-S algorithm for the completeness of a crash-recovery failure detector, and similarly for other QoS metrics.

Sistemas computacionais são constituídos por componentes de hardware e software que podem eventualmente falhar. Por esse motivo, o mecanismo de transação sempre foi imprescindível para a construção de sistemas robustos. O suporte transacional para a tecnologia Web services foi definido em agosto de 2005, num conjunto de três especificações denominadas WS-Coordination, WS-AtomicTransaction e WS-BusinessActivity. Juntas, essas especificações definem um alicerce sobre o qual aplicações robustas baseadas em Web services podem ser construídas. Nesta dissertação realizamos um estudo sobre transações atômicas em ambientes Web services. Em particular, estendemos o gerenciador de transações presente no servidor de aplicações JBoss, de modo que ele passasse a comportar transações distribuídas envolvendo Web services. Além disso, avaliamos o desempenho desse gerenciador de transações quando ele emprega cada um dos seguintes mecanismos de chamada remota: Web services/SOAP, CORBA/IIOP e JBoss Remoting. Finalmente, realizamos experimentos de escalabilidade e interoperabilidade. / Computing systems consist of a multitude of hardware and software components that may fail. For this reason, the transaction mechanism has always been essential for the development of robust systems. Transactional support for the Web services technology was defined in August 2005, in a set of three specifications, namely WS-Coordination, WS-AtomicTransaction, and WS-BusinessActivity. Together, such specifications enable the development of robust Web services applications. In this dissertation we studied atomic transactions in the Web services realm. Particularly, we added Web services atomic transaction support to the existing JBoss application server transaction manager. Furthermore, we evaluated the performance of this transaction manager when it employs each of the following remote method invocation mechanisms: Web services/SOAP, CORBA/IIOP and JBoss Remoting. Finally, we performed scalability and interoperability experiments.

Sistemas computacionais são constituídos por componentes de hardware e software que podem eventualmente falhar. Por esse motivo, o mecanismo de transação sempre foi imprescindível para a construção de sistemas robustos. O suporte transacional para a tecnologia Web services foi definido em agosto de 2005, num conjunto de três especificações denominadas WS-Coordination, WS-AtomicTransaction e WS-BusinessActivity. Juntas, essas especificações definem um alicerce sobre o qual aplicações robustas baseadas em Web services podem ser construídas. Nesta dissertação realizamos um estudo sobre transações atômicas em ambientes Web services. Em particular, estendemos o gerenciador de transações presente no servidor de aplicações JBoss, de modo que ele passasse a comportar transações distribuídas envolvendo Web services. Além disso, avaliamos o desempenho desse gerenciador de transações quando ele emprega cada um dos seguintes mecanismos de chamada remota: Web services/SOAP, CORBA/IIOP e JBoss Remoting. Finalmente, realizamos experimentos de escalabilidade e interoperabilidade. / Computing systems consist of a multitude of hardware and software components that may fail. For this reason, the transaction mechanism has always been essential for the development of robust systems. Transactional support for the Web services technology was defined in August 2005, in a set of three specifications, namely WS-Coordination, WS-AtomicTransaction, and WS-BusinessActivity. Together, such specifications enable the development of robust Web services applications. In this dissertation we studied atomic transactions in the Web services realm. Particularly, we added Web services atomic transaction support to the existing JBoss application server transaction manager. Furthermore, we evaluated the performance of this transaction manager when it employs each of the following remote method invocation mechanisms: Web services/SOAP, CORBA/IIOP and JBoss Remoting. Finally, we performed scalability and interoperability experiments.

Replicated systems are a kind of distributed systems whose main goal is to ensure that computer systems are highly available, fault tolerant and provide high performance. One of the last trends in replication techniques managed by replication protocols, make use of Group Communication Sys- tem, and more specifically of the communication primitive atomic broadcast for developing more eficient replication protocols. An important aspect in these systems consists in how they manage the disconnection of nodes {which degrades their service{ and the connec- tion/reconnection of nodes for maintaining their original support. This task is delegated in replicated systems to recovery protocols. How it works de- pends specially on the failure model adopted. A model commonly used for systems managing large state is the crash-recovery with partial amnesia be- cause it implies short recovery periods. But, assuming it implies arising several problems. Most of them have been already solved in the literature: view management, abort of local transactions started in crashed nodes { when referring to transactional environments{ or for example the reinclu- sion of new nodes to the replicated system. Anyway, there is one problem related to the assumption of this second failure model that has not been completely considered: the amnesia phenomenon. Phenomenon that can lead to inconsistencies if it is not correctly managed. This work presents this inconsistency problem due to the amnesia and formalizes it, de ning the properties that must be ful lled for avoiding it and de ning possible solutions. Besides, it also presents and formalizes an inconsistency problem {due to the amnesia{ which appears under a speci c sequence of events allowed by the majority partition progress condition that will imply to stop the system, proposing the properties for overcoming it and proposing di erent solutions. As a consequence it proposes a new majority partition progress condition. In the sequel there is de / De Juan Marín, R. (2008). Crash recovery with partial amnesia failure model issues [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/3302 / Palancia