6,375 research outputs found
Implicit Simulations using Messaging Protocols
A novel algorithm for performing parallel, distributed computer simulations
on the Internet using IP control messages is introduced. The algorithm employs
carefully constructed ICMP packets which enable the required computations to be
completed as part of the standard IP communication protocol. After providing a
detailed description of the algorithm, experimental applications in the areas
of stochastic neural networks and deterministic cellular automata are
discussed. As an example of the algorithms potential power, a simulation of a
deterministic cellular automaton involving 10^5 Internet connected devices was
performed.Comment: 14 pages, 3 figure
Efficient computation of hashes
The sequential computation of hashes at the core of many distributed storage systems and found, for example, in grid services can hinder efficiency in service quality and even pose security challenges that can only be addressed by the use of parallel hash tree modes. The main contributions of this paper are, first, the identification of several efficiency and security challenges posed by the use of sequential hash computation based on the Merkle-Damgard engine. In addition, alternatives for the parallel computation of hash trees are discussed, and a prototype for a new parallel implementation of the Keccak function, the SHA-3 winner, is introduced
A Fault Tolerant, Dynamic and Low Latency BDII Architecture for Grids
The current BDII model relies on information gathering from agents that run
on each core node of a Grid. This information is then published into a Grid
wide information resource known as Top BDII. The Top level BDIIs are updated
typically in cycles of a few minutes each. A new BDDI architecture is proposed
and described in this paper based on the hypothesis that only a few attribute
values change in each BDDI information cycle and consequently it may not be
necessary to update each parameter in a cycle. It has been demonstrated that
significant performance gains can be achieved by exchanging only the
information about records that changed during a cycle. Our investigations have
led us to implement a low latency and fault tolerant BDII system that involves
only minimal data transfer and facilitates secure transactions in a Grid
environment.Comment: 18 pages; 10 figures; 4 table
Coordination-Free Byzantine Replication with Minimal Communication Costs
State-of-the-art fault-tolerant and federated data management systems rely on fully-replicated designs in which all participants have equivalent roles. Consequently, these systems have only limited scalability and are ill-suited for high-performance data management. As an alternative, we propose a hierarchical design in which a Byzantine cluster manages data, while an arbitrary number of learners can reliable learn these updates and use the corresponding data.
To realize our design, we propose the delayed-replication algorithm, an efficient solution to the Byzantine learner problem that is central to our design. The delayed-replication algorithm is coordination-free, scalable, and has minimal communication cost for all participants involved. In doing so, the delayed-broadcast algorithm opens the door to new high-performance fault-tolerant and federated data management systems. To illustrate this, we show that the delayed-replication algorithm is not only useful to support specialized learners, but can also be used to reduce the overall communication cost of permissioned blockchains and to improve their storage scalability
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