Enabling Lightweight Transactions with Precision Time

Lightweight Inter-transaction Caching with Precise Clocks and Dynamic Self-invalidation

“…OCC with physical time leverages precise clocks only for performance: if clocks get out of synch, transactions may get spuriously aborted but no transaction is committed incorrectly, irrespective of the clock skew [2]. KAIROS synchronizes client clocks with the Precision Time Protocol(PTP) [18], which has been shown to reduce abort rates with OCC [32].…”

“…These stores use sharding to spread data across multiple replica groups for scalable throughput and high availability. They increasingly incorporate low-latency storage media on the servers: DRAM [11,12,24,35], non-volatile memory (NVM) [29], or solid-state drives (SSDs) [32].…”

“…This paper presents KAIROS 1 , a transactional key-value store that supports inter-transaction caching without explicit invalidations. KAIROS follows Milana [32] in using precise synchronized clocks [9,16,18,25] to enable physical time-based consistency integrated with transactional concurrency control, and adds support for inter-transaction caching. Our prototype of KAIROS uses Precision Time Protocol (PTP) [18]), 1 KAIROS means "appropriate time" in Greek.…”

“…Numerous works use OCC for ACID transactions [2, 6, 10-12, 24, 32, 44, 45]. Among these, Milana [32], Centiman [10] and Sundial [44] are most closely related to KAIROS. Milana [32] uses precise clocks to enhance OCC and reduce transaction abort rates, Centiman [10] performs sharded transaction validation and Sundial [44] supports inter-transaction caching using logical timebased leases.…”

“…Among these, Milana [32], Centiman [10] and Sundial [44] are most closely related to KAIROS. Milana [32] uses precise clocks to enhance OCC and reduce transaction abort rates, Centiman [10] performs sharded transaction validation and Sundial [44] supports inter-transaction caching using logical timebased leases. However, we are not aware of any prior work that performs dynamic self-invalidation of data from client caches or uses an analytical model for calcu- 2 It is important to distinguish two similar terms that are independent: validation refers to a step of optimistic concurrency control that occurs when a client transaction prepares to commit, while invalidation refers to a server callback to flush a stale value from a client cache.…”