Preserving reciprocal consistency in distributed graph databases

Abstract

Our earlier work identifies reciprocal consistency as an important property that must be preserved in distributed graph databases. It also demonstrates that a failure to do so seriously undermines the integrity of the database itself in the long term. Reciprocal consistency can be maintained as a part of enforcing any known isolation guarantee and such an enforcement is also known to lead to reduction in performance. Therefore, in practice, distributed graph databases are often built atop BASE databases with no isolation guarantees, benefiting from good performance but leaving them susceptible to corruption due to violations of reciprocal consistency. This paper designs and presents a lightweight, locking-free protocol and then evaluates the protocol's abilities to preserve reciprocal consistency and also offer good throughput. Our evaluations establish that the protocol can offer both integrity guarantees and sound performance when the value of its parameter is chosen appropriately. CCS Concepts. • Information systems → Database transaction processing; Graph-based database models.

Towards Testing ACID Compliance in the LDBC Social Network Benchmark

“…Looking ahead, in the short term, we will include these tests in the LDBC SNB specification [3] and use them for auditing the ACID-compliance of SUTs. In the long term, we plan to extend the tests to incorporate complex consistency constraints and add tests specifically designed for distributed databases [21].…”

“…If version x i precedes version x j and y j precedes version y i a G0 anomaly has occurred. Preventing G0 is especially important in a graph database in to order to maintain Reciprocal Consistency [21]. Definition.…”