Concurrent Certifications by Intervals of Timestamps in Distributed Database Systems

Boksenbaum, Claude; Cart, Michelle; Ferrié, Jean; Pons, Jean‐François

doi:10.1109/tse.1987.233178

Cited by 43 publications

(10 citation statements)

References 14 publications

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“…Similar to Sundial, previous concurrency control protocols have also used timestamp ranges to dynamically determine the transactions' logical commit timestamps. The technique, first proposed as dynamic timestamp allocation (DTA), was applied to both 2PL protocols for deadlock detection [8] and OCC protocols [12,29,30]. More recently, similar techniques have been applied to multiversion concurrency control protocols [34], as well as to MaaT, a single-version distributed concurrency control protocol [35].…”

Section: Sundial Vs Maatmentioning

confidence: 99%

Sundial

Xia

Pavlo

et al. 2018

Proc. VLDB Endow.

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Distributed transactions suffer from poor performance due to two major limiting factors. First, distributed transactions suffer from high latency because each of their accesses to remote data incurs a long network delay. Second, this high latency increases the likelihood of contention among distributed transactions, leading to high abort rates and low performance.We present Sundial, an in-memory distributed optimistic concurrency control protocol that addresses these two limitations. First, to reduce the transaction abort rate, Sundial dynamically determines the logical order among transactions at runtime, based on their data access patterns. Sundial achieves this by applying logical leases to each data element, which allows the database to dynamically calculate a transaction's logical commit timestamp. Second, to reduce the overhead of remote data accesses, Sundial allows the database to cache remote data in a server's local main memory and maintains cache coherence. With logical leases, Sundial integrates concurrency control and cache coherence into a simple unified protocol. We evaluate Sundial against state-of-the-art distributed concurrency control protocols. Sundial outperforms the next-best protocol by up to 57% under high contention. Sundial's caching scheme improves performance by up to 4.6× in workloads with high access skew. PVLDB Reference Format:

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Section: Sundial Vs Maatmentioning

confidence: 99%

Sundial

Xia

Pavlo

et al. 2018

Proc. VLDB Endow.

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“…Dynamic timestamp interval allocation has been proposed to address the read-write conflicts [9]. Whenever a transaction requests a data access, the system must check for and record the valid timestamp interval for each transaction on the data object accessed.…”

Section: Issues Of Transaction Processing In Broadcast Environmentsmentioning

confidence: 99%

On transaction processing with partial validation and timestamp ordering in mobile broadcast environments

Lee

Lam

Son

et al. 2002

IEEE Trans. Comput.

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Conventional concurrency control protocols are inapplicable in mobile broadcast environments due to a number of constraints of wireless communications. Previous studies are focused on efficient processing of read-only transactions at the mobile clients, neglecting update transactions. In this paper, we design a new protocol for processing both read-only and update mobile transactions. The protocol can detect data conflicts at an early stage at the mobile clients and resolve data conflicts flexibly using dynamic adjustment of timestamp ordering. Early data conflict detection saves processing and communication resources, while dynamic adjustment of timestamp ordering allows more schedules of transaction executions such that unnecessary transaction aborts can be avoided. We performed extensive simulation studies to evaluate the effectiveness of these two features for the performance of the new protocol. The analysis of simulation results showed that both features are effective and contribute differently to the satisfactory performance of the protocol.

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“…Similarly to serialization graph testing [Bernstein et al 1987], this is at the cost of added space and complexity. The validation scheme based on "intervals of timestamps" is intended to improve the success rate in a distributed database environment [Boksenbaum et al 1987].…”

Section: Concurrency Controlmentioning

confidence: 99%

Concurrency control

Thomasian

1998

ACM Comput. Surv.

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Standard locking (two-phase locking with on-demand lock requests and blocking upon lock conflict) is the primary concurrency control (CC) method for centralized databases. The main source of performance degradation with standard locking is blocking, whereas transaction (txn) restarts to resolve deadlocks have a secondary effect on performance. We provide a performance analysis of standard locking that accurately estimates its performance degradation leading to thrashing. We next introduce two sets of methods to cope with its performance limitations. Restartoriented locking methods selectively abort txns to increase the level of concurrency for active txns with respect to standard locking in high-contention environments. For example, the running-priority method aborts blocked txns based on the essential blocking principle, which only allows blocking by active txns. The waitdepth-limited (WDL) method further minimizes wasted processing by basing abort decisions on the progress made by a txn. Restart waiting serves as a load-control mechanism by deferring the restart of an aborted txn until conflicting txns have left the system. These two methods have performance superior to other restartoriented methods and standard locking in high-contention environments. In twophase processing methods an aborted txn may continue its first phase of execution in "virtual" mode, that is, without requesting any locks, prefetching data for its second execution phase. The second execution phase is shorter since no disk I/O is required, resulting in a lower effective degree of txn concurrency and less data contention. This method is effective provided access invariance prevails; that is, txns access the same set of objects in the second phase as they did in the first. The optimistic die method is appropriate for the first phase and the optimistic kill method for further phases. Lock preclaiming instead of the optimistic kill method in the second phase prevents further restarts, which is a weak point of the optimistic CC method due to the quadratic effect, that is, the probability of failed validation increases as the square of txn size. Several two-phase processing methods are described and shown to outperform restart-oriented locking methods in high-contention environments provided adequate hardware resources are available. This tutorial reviews CC methods based on standard locking, restartoriented locking methods, two-phase processing methods including optimistic CC, and hybrid methods (combining optimistic CC and locking) in centralized systems. Its main goals are as follows: (i) succinctly specify CC methods of interest; (ii) describe models for performance evaluation of CC methods, including new models that alleviate some of the shortcomings of models used in earlier studies; (iii) compare the performance of CC methods; (iv) list insights gained from analytic and simulation studies; (v) review methods to relieve the level of lock contention: special methods for indices and aggregate data; modified txn structures; and relaxed level...

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Concurrent Certifications by Intervals of Timestamps in Distributed Database Systems

Cited by 43 publications

References 14 publications

Sundial

Sundial

On transaction processing with partial validation and timestamp ordering in mobile broadcast environments

Concurrency control

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