Failure Types Sample Clauses
Failure Types. In a distributed system, the network components may not always work well. A node is said to be fault- free if it follows protocol specifications during the execution of a protocol; otherwise, the node is said to be faulty. The symptoms of node failure can be classified into two categories. There are dormant fault and malicious fault (also called as the Byzantine fault) [13]. The dormant faults of nodes include crashes and omission. A crash fault happens when a node is broken. An omission fault takes place when a node fails to transmit or receive a message on time or at all. On a malicious fault, the behavior of a faulty node is unpredictable and arbitrary. The message transmitted by a malicious faulty node is random or arbitrary. It is the most damaging failure type and causes the worst problem. That is, if the agreement problem can be solved in a malicious fault case, then the agreement problem can also be solved in other failure mode. Therefore, in this study, malicious faults are investigated, and the means by which fault-free nodes may reach agreement in the FC-IoT platform are explored. In addition, ▇▇▇▇▇▇▇▇ and ▇▇▇▇▇ also indicate that BA in an asynchronous network is impossible even if only one crash faulty node [3]. Hence, the assumption of underlying FC-IoT is synchronous.
Failure Types. There are three kinds of symptoms a faulty component may have. They are crash, omission and malicious fault. We can classify these three kinds of symptoms into two categories. They are dormant fault (include crashes and omissions) and malicious fault [9] .
Failure Types. According to previous literature, the symptoms of a faulty processor/TM can be classified into two categories, which are dormant fault (including crash or omission/stuck-at) and malicious fault [18]. The symptom of a faulty processor may be crash fault or omission fault and the symptom of a faulty TM may be crash fault or stuck-at fault, generally called dormant fault. A crash fault happens when a processor simply freezes, but behaves correctly before freezing. An omission fault takes place when a processor fails to respond to messages on time or at all. A stuck-at fault means that the processor always receives the same value via the faulty TM. A dormant fault is detectable by other processors in synchronous system if a transmitted message is encoded appropriately by either the Non-Return-to-Zero code or the Manchester code before transmission [12]. Another symptom of a faulty processor/TM is malicious fault. On the occasion of a malicious fault occurring, the behavior of a malicious faulty processor/TM is unpredictable and arbitrary. The malicious faulty processor/TM may fake, lose, or mangle messages. Thus, it is the most extreme failure type and causes the serious problems. If a common agreement can be reached at the presence of a malicious fault, then it can also be reached in the other failure modes. The dual failure mode on processor/TM contains both a dormant fault and malicious fault existing simultaneously in the network. In previous studies, the main points seem to focus on the processor/TM with a malicious fault only. However, the failure type of a faulty processor/TM may be dormant or malicious [18], so this scenario would decrease the maximum number of tolerable faulty components of a BA protocol, when there are dormant faulty components existing in the system. Therefore, if we can solve the BA problem with a dual failure mode on processor/TM (generalized case); the capacity of fault tolerance can be enlarged.