Multi-version Coding with Side Information

by   Ramy E. Ali, et al.

In applications of storage systems to modern key-value stores, the stored data is highly dynamic due to frequent updates from the system write clients. The multi-version coding problem has been formulated to study the cost of storing dynamic data in asynchronous distributed storage systems. In this problem, previous work considered a completely decentralized system where a server is not aware of which versions of the data are received by the other servers. In this paper, we relax this assumption and study a system where a server may acquire side information of the versions propagated to some other servers. In particular, we study a storage system with n servers that store ν totally ordered independent versions of a message. Each server receives a subset of these ν versions that defines the state of that server. Assuming that the servers are distributed in a ring, a server is aware of which versions have been received by its h-hop neighbors. If the server is aware of the states of (n-2) other servers, we show that this side information can result in a better storage cost as compared with the case where there is no side information. Through an information-theoretic converse, we identify scenarios where, even if the server is aware of the states of (n-3)/2 other servers, the side information may not help in improving the worst-case storage cost beyond the case where servers have no side information.


page 1

page 2

page 3

page 4


Harnessing Correlations in Distributed Erasure Coded Key-Value Stores

Motivated by applications of distributed storage systems to cloud-based ...

CausalEC: A Causally Consistent Data Storage Algorithm based on Cross-Object Erasure Coding

Causally consistent distributed storage systems have received significan...

Sequential Checking: Reallocation-Free Data-Distribution Algorithm for Scale-out Storage

Using tape or optical devices for scale-out storage is one option for st...

Quantifying the Cost of Privately Storing Data in Distributed Storage Systems

Consider a user who wishes to store a file in multiple servers such that...

The Capacity of Classical Summation over a Quantum MAC with Arbitrarily Distributed Inputs and Entanglements

The Σ-QMAC problem is introduced, involving S servers, K classical (𝔽_d)...

How Hard is Asynchronous Weight Reassignment? (Extended Version)

The performance of distributed storage systems deployed on wide-area net...

Storage-Efficient Shared Memory Emulation

We study the design of storage-efficient algorithms for emulating atomic...

Please sign up or login with your details

Forgot password? Click here to reset