YCSB+T: Benchmarking web-scale transactional databases

Database system benchmarks like TPC-C and TPC-E focus on emulating database applications to compare different DBMS implementations. These benchmarks use carefully constructed queries executed within the context of transactions to exercise specific RDBMS features, and measure the throughput achieved. Cloud services benchmark frameworks like YCSB, on the other hand, are designed for performance evaluation of distributed NoSQL key-value stores, early examples of which did not support transactions, and so the benchmarks use single operations that are not inside transactions. Recent implementations of web-scale distributed NoSQL systems like Spanner and Percolator, offer transaction features to cater to new web-scale applications. This has exposed a gap in standard benchmarks. We identify the issues that need to be addressed when evaluating transaction support in NoSQL databases. We describe YCSB+T, an extension of YCSB, that wraps database operations within transactions. In this framework, we include a validation stage to detect and quantify database anomalies resulting from any workload, and we gather metrics that measure transactional overhead. We have designed a specific workload called Closed Economy Workload (CEW), which can run within the YCSB+T framework. We share our experience with using CEW to evaluate some NoSQL systems.