ThespisDIIP: Distributed Integrity Invariant Preservation.

Thespis is a distributed database middleware that leverages the Actor model to implement causal consistency over an industry-standard DBMS, whilst abstracting complexities for application developers behind a REST open-protocol interface. ThespisDIIP is an extension that treats the concept of integrity invariance preservation for the class of problems where value changes must be satisfied according to a Linear Arithmetic Inequality constraint. An example of this constraint is a system enforcing a constraint that a transaction is only accepted if there are sufficient funds in a bank account. Our evaluation considers correctness, performance and scalability aspects of ThespisDIIP. We also run empirical experiments using YCSB to show the efficacy of the approach for a variety of workloads and a number of conditions, determining that integrity invariants are preserved in a causally-consistent distributed database, whilst minimising latency in the user’s critical path.