We study the ability of different shared object types to solve recoverable consensus using non-volatile shared memory in a system with crashes and recoveries. In particular, we compare the difficulty of solving recoverable consensus to the difficulty of solving the standard wait-free consensus problem in a system with halting failures. We focus on the model where individual processes may crash and recover and the large class of object types that are equipped with a read operation. We characterize the readable object types that can solve recoverable consensus among a given number of processes. Using this characterization, we show that the number of processes that can solve consensus using a readable type can be larger than the number of processes that can solve recoverable consensus using that type, but only slightly larger.
@article{arxiv.2205.14213,
title = {When Is Recoverable Consensus Harder Than Consensus?},
author = {Carole Delporte-Gallet and Panagiota Fatourou and Hugues Fauconnier and Eric Ruppert},
journal= {arXiv preprint arXiv:2205.14213},
year = {2022}
}
Comments
A shorter version of this paper will appear in Proceedings of the 2022 ACM Symposium on Principles of Distributed Computing (PODC '22), July 25-29, 2022, Salerno, Italy, https://doi.org/10.1145/3519270.3538418