Proceedings of the 27th ACM Symposium on Applied Computing, Dependable and Adaptive Distributed Systems Track, Riva del Garda (Trento), Italy, March 2012
Algorithms for solving distributed systems problems often
use timeouts as a means to achieve progress. They are designed
in a way that safety is always preserved despite timeouts being
too small or too large. A conservatively large
static timeout value is usually selected, such that the overall
system performance is acceptable in the normal case. This
approach is good enough in stable environments, but it may
compromise performance in more dynamic settings, such as
in wireless networks. In this case, a better approach is to
dynamically adjusting timeouts according to the observed
network conditions.
This paper clearly illustrates the achievable improvements
and thus justifies the importance of using adaptive protocols
in dynamic environments. We describe our pragmatic
approach to transform a static timeout-based consensus protocol
for ad hoc wireless networks into a fully autonomic and
adaptive solution. Our comparative experiments, performed
in a wireless environment, show that in contrast with the
original static protocol, the adaptive solution leads to an
almost constant bandwidth utilization despite increasing the
number of consensus participants, and the overall consensus
execution time increases linearly instead of exponentially.
@inproceedings{Dixit:12a,
author = {Dixit, M\^{o}nica and Moniz, Henrique and Casimiro, Ant\'{o}nio},
title = {Timeout-based adaptive consensus: improving performance through adaptation},
booktitle = {Proceedings of the 27th Annual ACM Symposium on Applied Computing},
series = {SAC '12},
year = {2012},
isbn = {978-1-4503-0857-1},
location = {Trento, Italy},
pages = {492--497},
numpages = {6},
url = {http://doi.acm.org/10.1145/2245276.2245371},
doi = {10.1145/2245276.2245371},
acmid = {2245371},
publisher = {ACM},
address = {New York, NY, USA},
keywords = {adaptation, consensus, performance, probabilistic monitoring},
abstractURL = "http://www.di.fc.ul.pt/~casim/papers/dads12/dads12.html",
documentURL = "http://www.di.fc.ul.pt/~casim/papers/dads12/dads12.pdf",
}