Blockchain has come a long way: a system that was initially proposed specifically for cryptocurrencies is now being adapted and adopted as a general-purpose transactional system. A blockchain is also a distributed system, and as such it shares some similarities with distributed database systems. Existing works that compare blockchains and distributed database systems focus mainly on high-level properties, such as security and throughput. They stop short of showing how the underlying design choices contribute to the overall differences. Our paper is to fill this important gap . In this paper, we perform a twin study of blockchains and distributed database systems as two types of transactional systems. We propose a taxonomy that helps illustrate their similarities and differences. In particular, we compare the systems along four dimensions: replication, concurrency, storage, and sharding. We discuss how the design choices have been driven by the system's goals: blockchain's goal is security , whereas the distributed database's goal is performance . We then conduct an extensive and in-depth performance study on two blockchains, namely Quorum and Hyperledger Fabric, and three distributed databases, namely CockroachDB, TiDB and etcd. We demonstrate how the different design choices in the four dimensions lead to different performance. In addition, we show that for most workloads, blockchain's performance is still lagging far behind that of a distributed database. However, the gap is not as significant as previously reported, and under high contention or constrained workloads, blockchains and databases are even comparable. Our work provides a framework for exploring the design space of hybrid database-blockchain systems .
Blockchain has come a long way: a system that was initially proposed specifically for cryptocurrencies is now being adapted and adopted as a general-purpose transactional system. As blockchain evolves into another data management system, the natural question is how it compares against distributed database systems. Existing works on this comparison focus on high-level properties, such as security and throughput. They stop short of showing how the underlying design choices contribute to the overall differences. Our work fills this important gap and provides a principled framework for analyzing the emerging trend of blockchain-database fusion. We perform a twin study of blockchains and distributed database systems as two types of transactional systems. We propose a taxonomy that illustrates the dichotomy across four dimensions, namely replication, concurrency, storage, and sharding. Within each dimension, we discuss how the design choices are driven by two goals: security for blockchains, and performance for distributed databases. To expose the impact of different design choices on the overall performance, we conduct an in-depth performance analysis of two blockchains, namely Quorum and Hyperledger Fabric, and two distributed databases, namely TiDB, and etcd. Lastly, we propose a framework for back-of-the-envelope performance forecast of blockchain-database hybrids .
R
A blockchain is also a distributed system, and as such it shares some similarities with
As blockchain evolves into another data management system, the natural question is how it compares against
R
that compare blockchains and distributed database systems focus mainly
on this comparison focus
R
paper is to fill
work fills
R
. In this paper, we
and provides a principled framework for analyzing the emerging trend of blockchain-database fusion. We
R
helps illustrate their similarities and differences. In particular, we compare the systems along four dimensions:
illustrates the dichotomy across four dimensions, namely
R
We
Within each dimension, we
R
have been driven by the system's goals: blockchain's goal is security , whereas the distributed database's goal is performance . We then conduct an extensive and
are driven by two goals: security for blockchains, and performance for distributed databases. To expose the impact of different design choices on the overall performance, we conduct an
R
study on
analysis of
R
three
two
R
CockroachDB, TiDB
TiDB,
R
We demonstrate how the different design choices in the four dimensions lead to different performance. In addition, we show that for most workloads, blockchain's performance is still lagging far behind that of a distributed database. However, the gap is not as significant as previously reported, and under high contention or constrained workloads, blockchains and databases are even comparable. Our work provides a framework for exploring the design space of hybrid database-blockchain systems
Lastly, we propose a framework for back-of-the-envelope performance forecast of blockchain-database hybrids