Raft is a state-of-the-art consensus algorithm for state replication over a distributedsystem of nodes. According to Raft, all state updates occurring anywhere in the system are forwarded to the leader, which is elec...
详细信息
Raft is a state-of-the-art consensus algorithm for state replication over a distributedsystem of nodes. According to Raft, all state updates occurring anywhere in the system are forwarded to the leader, which is elected among the system nodes to collect and replicate these updates to all other nodes. Thus, the time required for the state replication, named as system response time, depends on the delays between the leader and all other nodes. After multiple node failures and leadership transitions, each node can be leader with a probability that affects the expected response time. The leadership probabilities, in turn, are affected by the random intervals that nodes are waiting, after detecting a leader failure and before competing for the successive leadership. The Raft designers suggest the ranges of these intervals to be equal for all nodes. However, this may result in increased expected response time. In this paper, mathematical models are presented for estimating the ranges resulting in the desired leadership probabilities. The presented theoretical results are also confirmed by testbed experimentation with an open-source and widely used Raft implementation.
Verification of distributedsystem protocols either suffers from state-space explosion in composing the combined behavior of a number of identical participating processes or lacs in automated theorem proving technique...
详细信息
ISBN:
(纸本)9781467319522;9781467319515
Verification of distributedsystem protocols either suffers from state-space explosion in composing the combined behavior of a number of identical participating processes or lacs in automated theorem proving technique to handle it. HS leader election protocol in a bidirectional synchronous ring is one such distributedsystem protocol whose verification also faces the same difficulties. A new mechanized verification framework proposed recently by the authors combines the tableau based theorem proving approach and model checking. It claims to have addressed the issues. In this paper authors have used this framework to verify the liveness property of HS Leader Election Protocol in a bidirectional synchronous ring to show that it can be effectively mechanized.
In the industry distributedsystems are used increasingly for solving automation problems. Consequently central automation structures become less important [I]. Today a multitude of field bus systems is available for ...
详细信息
ISBN:
(纸本)9789806560543
In the industry distributedsystems are used increasingly for solving automation problems. Consequently central automation structures become less important [I]. Today a multitude of field bus systems is available for communication in distributed automation systems. Apart from basic technical conditions and economic considerations the real-time behavior must be considered to reach a decision for a special field-bus-system [2]. in this project typical real-time scenarios were analyzed and put into practice for an experimental setup. The CAN-bus was used to build up the data communication for a closed-loop control system. In an experimental setup the real-time behavior of a distributed CAN based communication system was examined. The measuring data were analyzed and the visualization for real-time violations was developed.
作者：
LEMKIN, PLIPKIN, LImage Processing Unit
Division of Cancer Biology and Diagnosis National Center Institute National Institute of Health Bethesda MD 20205 USA
This paper presents an example of a distributed monitor system, BMON-2, which was developed and is in daily use in a biological image processing environment. Useful aspects of such a system are discussed, particularly...
详细信息
This paper presents an example of a distributed monitor system, BMON-2, which was developed and is in daily use in a biological image processing environment. Useful aspects of such a system are discussed, particularly those which make for easier biologist-user interaction and system extensibility. The principles of extension of the distributed monitor to a time-shared computer system is outlined.
暂无评论