Sundial: Harmonizing Concurrency Control and Caching in a Distributed OLTP Database Management System Xiangyao Yu, Yu Xia, Andrew Pavlo♠ Daniel Sanchez, Larry Rudolph|, Srinivas Devadas Massachusetts Institute of Technology, ♠Carnegie Mellon University, |Two Sigma Investments, LP
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[email protected] ABSTRACT and foremost, long network delays lead to long execution time of Distributed transactions suffer from poor performance due to two distributed transactions, making them slower than single-partition major limiting factors. First, distributed transactions suffer from transactions. Second, long execution time increases the likelihood high latency because each of their accesses to remote data incurs a of contention among transactions, leading to more aborts and per- long network delay. Second, this high latency increases the likeli- formance degradation. hood of contention among distributed transactions, leading to high Recent work on improving distributed concurrency control has abort rates and low performance. focused on protocol-level and hardware-level improvements. Im- We present Sundial, an in-memory distributed optimistic concur- proved protocols can reduce synchronization overhead among trans- rency control protocol that addresses these two limitations. First, to actions [22, 35, 36, 46], but can still limit performance due to high reduce the transaction abort rate, Sundial dynamically determines coordination overhead (e.g., lock blocking). Hardware-level im- the logical order among transactions at runtime, based on their data provements include using special hardware like optimized networks access patterns. Sundial achieves this by applying logical leases to that enable low-latency remote memory accesses [20, 48, 55], which each data element, which allows the database to dynamically calcu- can increase the overall cost of the system.