Mathematical Sciences
same output
2003-03-14
consensus problem
consensus
model
clock
fault-tolerant systems
asynchronous model
absence of failures
en
absence
message delay
output
finite period
safety
building blocks
bounds
https://scigraph.springernature.com/explorer/license/
input
addition
chapters
consensus algorithm
period
half
important building blocks
run
problem
Open Questions on Consensus Performance inWell-Behaved Runs
chapter
correct processes
2022-05-20T07:42
process
algorithm
We consider the consensus problem in a message-passing system where processes can crash: Each process has an input, and each correct process must decide on an output, such that all correct processes decide on the same output, and this output is the input of one of the processes. Consensus is an important building block for fault-tolerant systems. It is well-known that consensus is not solvable in an asynchronous model even if only one process can crash [7.13]. However, real systems are not completely asynchronous. Some partially synchronous models [7.12], [7.10] where consensus is solvable better approximate real systems.We consider a partial synchronymodel defined as follows [7.12]1: (1) processes have bounded drift clocks; (2) there are known bounds on processing times and message delays; and (3) less than half of the processes can crash. In addition, this model allows the system to be unstable, where the bounds in (2) do not hold for an unbounded but finite period, but it must eventually enter a stableperiod where the bounds do hold.A consensus algorithm for the partial synchrony model never violates safety, and guarantees liveness once the system becomes stable. Algorithms for this model are called indulgent in [7.16]. What can we say about the running time of consensus algorithms in a partial synchrony model? Unfortunately, even in the absence of failures, any consensus algorithm in this model is bound to have unbounded running times, by [7.13].
synchrony model
false
https://doi.org/10.1007/3-540-37795-6_7
2003-03-14
delay
liveness
questions
system
synchronous model
time
35-39
block
message-passing systems
running time
failure
real system
Zhao
Ben Y.
André
Schiper
dimensions_id
pub.1012746036
Springer Nature - SN SciGraph project
Department of Electrical Engineering, The Technion, 32000, Haifa, Israel
Department of Electrical Engineering, The Technion, 32000, Haifa, Israel
Weatherspoon
Hakim
Rajsbaum
Sergio
Applied Mathematics
Keidar
Idit
978-3-540-00912-2
Future Directions in Distributed Computing
978-3-540-37795-5
UNAM, Instituto de Matemáticas, Mexico
UNAM, Instituto de Matemáticas, Mexico
Springer Nature
Alex A.
Shvartsman
10.1007/3-540-37795-6_7
doi