S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering,Tempe, AZ, February 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... requirement defined by serializability [2] most real time concurrency control schemes considered in the literature are based on two phase locking (2PL) 7] In recent years, various real time concurrency control methods have been proposed for the single site RTDBS by modifying 2PL (e.g. [18, 24, 28]) However, 2PL has some inherent problems such as the possibility of deadlocks as well as long and unpredictable blocking times. These problems appear to be serious in real time transaction processing since real time transactions need to meet their timing constraints, in addition to consistency ....

....optimistic concurrency control methods is not only to incorporate information about the criticality of transactions for conflict resolution but also to design methods that minimize the number of transactions to be restarted. This paper presents a method based on integrated concurrency control [2, 28] ,which extents the optimistic concurrency control method with transaction attributes. The basic ideas of three proposed optimistic concurrency control methods are presented and showed how they are used in an integrated concurrency controller. The rest of the paper is organized as follows. Section ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Proceedings of the 8th International Conference on Data Engineering, pages 527--534, Tempe, Arizona, USA, 1992. IEEE Computer Society Press.

....the proposed modifications are based on dynamic two phase locking (D2PL) Most probably this is due to the simplicity of D2PL and its popularity for conventional database systems. One of the earliest proposals in real time transaction processing protocol was Hight Priority Two Phase Locking (H2PL) [2, 30]. In addition, to reduce blocking time, priority inheritance [15] and conditional priority inheritance [15] have been suggested. In these protocols a lower priority transaction inherits a priority of the higher priority transaction. Hybrid Two Phase Locking (HB2PL) 16] adopts the concept of ....

Son, S. H., Park, S., and Lin, Y. (1992). An integrated real-time locking protocol. In Proceedings of 8th International Conference on Data Engineering, pages 527--534, IEEE Computer Society Press.

....transaction meet its deadline. Expectations about the performance of data priority based locking protocol were confirmed by experimental results [63, 65] Examples of other lock based concurrency control protocols developed for RTDBSs include those provided by Agrawal et al. 5] and by Son et al. [58]. The protocols presented in [5] were motivated from the observation that the blocking behavior of locking protocols can greatly degrade the performance of RTDBSs. A new relationship between locks, called ordered sharing, is used in the protocols to eliminate blocking of read and write operations ....

....The protocols aim to improve the overall system performance by exploiting any available slack in a transaction. It was shown through simulation that the proposed protocols can perform better than the priority abort protocol PA. A rather complex locking protocol was introduced by Son et al. [58] to be used in RTDBSs. In this protocol, the serialization order of active transactions is adjusted dynamically, making it possible for high priority transactions to be executed before lower priority transactions, while lower priority transactions may not have to be aborted in resolving data ....

S.H. Son, S. Park, Y.Lin `An Integrated Real-Time Locking Protocol', Proceedings of the 8th International Conference on Data Engineering, 1992, pp.527-534.

....investigated methods to apply the priority ceiling protocol as a basis for real time locking protocol in a distributed environment. Agrawal et al. 5] proposed a new locking approach, referred to as ordered sharing, which attempts to eliminate blocking of read and write operations in RTDBSs. In [42], Son et al. examined a priority driven locking protocol which decomposes the problem of concurrency control into two subproblems, namely read write synchronization and write write synchronization, and integrates the solutions to two subproblems considering transaction priorities. Kim and ....

S.H.Son, S.Park, Y.Lin, "An Integrated Real-Time Locking Protocol", 8th International Conference on Data Engineering, 1992, pp.527-534.

.... may suffer from an unlimited amount of priority inversion time, where priority inversion is a situation in which a higher priority transaction is blocked by a lower priority transaction [28] In the past decade, researchers have proposed various real time concurrency control protocols, e.g. [1, 8, 24, 29, 28, 30, 36], for single site as well as distributed RTDBS. In particular, 8, 28] proposed the idea of priority inheritance, which lets a lower priority transaction inherit the priority of a higher priority transaction which is blocked by the lower priority transaction, to reduce the number of priority ....

S.H. Son, S. Park and Y Lin. An Integrated Real-time Locking Protocol. In Proceedings of the International Conference on Data Engineering, Tempe, Arizona, pp. 527-534, IEEE Computer Society Press (1992).

....also the fact that data read by a transaction must be valid when a transaction read them and must stay valid until completion of the transaction. These requirements make existing CCP for conventional DB unacceptable for RTDBS. Most of CCPs for RTDBS are extensions of protocols for conventional DB [8, 10, 9, 11], but no of them can meet al..l timing requirements. 3 A Brief Summary of Duration Calculus In this section, we give a brief summary of Duration Calculus which will be used as the formalism to specify the models of DBS and RTDBS in this paper. For more details, readers are referred objects Temporal ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Eighth IEEE International Conference on Data Engineering, pages 527--534, Phoenix, Arizona, February 1992.

....are based on two phase locking (2PL) 15] 2PL has been studied extensively in traditional database systems and is being widely used in commercial databases. In recent years, various real time concurrency control methods have been proposed for the single site RTDBS by modifying 2PL (e.g. [5, 6, 27, 31, 46, 58, 75]) However, 2PL has some inherent problems such as the possibility of deadlocks as well as long and unpredictable blocking times. These problems appear to be serious in real time transaction processing since real time transactions need to meet their timing constraints, in addition to consistency ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Proceedings of the 8th International Conference on Data Engineering, pages 527--534, Tempe, Arizona, USA, 1992. IEEE Computer Society Press.

....the data objects. If the requested lock is used in conflicting mode by another transaction, the requesting transaction will be blocked until the lock is not in conflicting mode. One of the earliest suggestions of real time protocol based on D2PL is Hight Priority Two Phase Locking (H2PL) [1, 31] which uses the same priority for both CPU and data scheduling. In H2PL, if a higher priority transaction request to use a lock which is used by a lower priority transaction, the lower priority transaction must release the lock and restart. To reduce blocking time priority inheritance [14] and ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Proceedings of 8th International Conference on Data Engineering, pages 527--534, Los Alamitos, Calif., 1992. IEEE Computer Society, IEEE Computer Society Press. 17

....in a specified period of time because the price of the stock changes very fast. However, such failures would not be catastrophic. These systems are called soft or firm real time systems. Although significant research efforts have been made in the real time database area in last several years [1, 5, 8, 9, 10, 24, 28, 29], they are mainly focused on scheduling transactions in soft or firm realtime applications. As their applications do not require stringent timing constraints, most of their protocols adopt the best effort approach to scheduling transactions without a guarantee of meeting transaction s deadlines. ....

....priority transactions can have more chances to preempt lower priority transactions without causing data consistency problems. Thus, the update in workspace model is preferable in priority driven scheduling. In fact, several previous studies on real time concurrency controls have adopted this model [8, 13, 24]. 4.1. Dynamic Adjustment of Serialization Order We now examine the ways of enhancing the chances of a high priority transaction preempting a lower priority transaction by dynamically adjusting the serialization order induced by their data conflicts. One of the important properties of ....

S.H. Son, S. Park, and Y. Lin. An Integrated Real-Time Locking Protocol. Proceedings of the 8th International Conference on Data Engineering, USA, pp. 527-534, IEEE (1992).

....2PL s long and unpredictable blocking times damage its appeal for real time environments, where the primary performance criterion is meeting time constraints and not just preserving consistency requirements. Over the last few years, several alternatives to 2PL for RTDBMS have been explored [18, 14, 13, 16, 17, 20, 30]. In a recent study [5] we proposed a categorically different approach to concurrency control for RTDBMS. Our approach relies on the use of redundant computation to start on alternative schedules, once conflicts that threaten the consistency of the database are detected. These alternative ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....time critical scheduling methods to observe the timing requirements of transactions [30] A considerable amount of RTDBS research has been devoted to performance evaluation of time cognizant concurrency control protocols. However, the performance studies were either based on simulation (e.g. [1, 2, 3, 10, 11, 20, 23, 27, 28, 29]) or carried out on a RTDBS testbed (e.g. 14, 15] To the best of our knowledge, no analytic performance study has been reported so far involving the evaluation of concurrency control protocols in RTDBSs, which is the main contribution of this paper. 1 The behavior of concurrency control ....

S. H. Son, S. Park, Y. Lin `An Integrated Real-Time Locking Protocol', 8th International Conference on Data Engineering, pp.527-534, 1992.

....finishes successfully, the result is known. Thus several versions of the computation can be run, with different time bounds, guaranteeing an upper bound on the time to produce some result. Mena [Mena82] has classified concurrency control algorithms into two classes: optimistic algorithms (e.g. [Hari90b, Hari90a, Huan90, Kim91, Lin90, Son92]) and pessimistic algorithms (e.g. Abbo88, Stan88, Huan90, Sha91] Bestavros has proposed (in [Best92] a new approach, Speculative Concurrency Control (SCC) which incorporates redundant computation into concurrency control algorithms. Speculative concurrency control redundantly executes the ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....simultaneously. There has been a considerable amount of work in the area of RTDBSs. An extensive exploration of the issues is presented in [11, 19, 21] Most of the work in the RTDBS area has focused on the development and evaluation of priority cognizant concurrency control protocols (e.g. [1, 2, 4, 6, 8, 10, 12, 17, 18, 20]) Many proposed concurrency protocols have transferred assumptions and results from non RTDBSs in an unchallenged form to the realm of RTDBSs. The chain of thought underlying conventional concurrency control is the following: I O is 3 4 orders of magnitude slower than a main memory access. ....

S.H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Proceedings of the International Conference on Data Engineering, pp.527--534 (1992).

....also the fact that data read by a transaction must be valid when a transaction read them and must stay valid until completion of the transaction. These requirements make existing CCP for conventional DB unacceptable for RTDBS. Most of CCPs for RTDBS are extensions of protocols for conventional DB [8, 10, 9, 11], but no of them can meet al..l timing requirements. 3 A Brief Summary of Duration Calculus In this section, we give a brief summary of Duration Calculus which will be used as the formalism to specify the models of DBS and RTDBS in this paper. For more details, readers are referred Report No. 152, ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Eighth IEEE International Conference on Data Engineering, pages 527--534, Phoenix, Arizona, February 1992.

.... et al. 1992] Son et al. examined a priority driven locking protocol which decomposes the problem of concurrency control into two subproblems, namely read write synchronization and write write synchronization, and integrates the solutions to two subproblems considering transaction priorities [Son et al. 1992]. In [Kim and Srivastava 1991] new multiversion concurrency control algorithms were proposed to increase concurrency in RTDBSs. In [Ulusoy and Belford 1993] we described several real time concurrency control protocols and reported their relative performance in a single site RTDBS. The remainder ....

S.H. Son, S. Park, Y. Lin, An Integrated Real-Time Locking Protocol, 8th International Conference on Data Engineering, 527-534.

....of their timing constraints. These priorities are used with PCC based techniques [AGM88, ACL87, SZ88, HSTR89, Sin88, SRL88, SRSC91] to make it possible for urgent transactions to abort conflicting, less urgent ones (thus avoiding the hazards of blockages) and are used with OCC based techniques [Kor90, HCL90b, HCL90a, HSRT91, KS91, LS90, SPL92] to favor urgent transactions when conflicting, less urgent ones attempt to validate and commit (thus avoiding the hazards of restarts) In a recent study [Bes92] we proposed an approach to concurrency control that combines the advantages of both OCC and PCC protocols while avoiding their ....

....of lesser worth. Figure 10 shows the increased value added to the system that results from delaying the commitment of T 1 , thus allowing T o 2 to commit before its deadline and contribute a higher value to the system. Our approach for introducing delays is similar to those proposed in [AAJ92, HCL90a, SPL92]. Whenever a shadow T o u finishes its execution, we evaluate if it is advantageous to defer T o u s commitment. Finding the best point in time to commit a finished shadow T o u is a very hard optimization problem, since it requires the consideration of all possible serialization orders of ....

S. Son, S. Park, and Y. Lin. An integrated realtime locking protocol. In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....the performance of the transaction scheduling algorithms. Concurrency Control Techniques with Serializability: Concurrency control techniques for real time databases that use serializability as the correctness criteria include lock based protocols such as two phase locking and its variants [3, 1, 7, 60, 86, 88, 179, 180, 193, 214, 216], optimistic concurrency control protocols [74, 78, 88, 121] and timestamp ordering protocols [133, 195, 215] Using any of these techniques, conflicts between two real time transactions or between one real time transaction and a set of real time transactions are detected. For lock based ....

Son, S. H., Park, S., and Lin, Y., "An Integrated Real-Time Locking Protocol," in Proceedings of the International Conference on Data Engineering, pp. 527--534, 1992.

....blocking times that damage its appeal for real time environments, where the primary performance criterion is meeting time constraints and not just preserving consistency requirements. Over the last few years, several alternatives to 2PL for RTDBMS have been explored, proposed, and investigated [Kort90, Hari90b, Hari90a, Huan91, Kim91, Lin90, Son92]. In a recent study [Best92b] Bestavros proposed a categorically different approach to concurrency control for RTDBMS. His approach relies on the use of redundant computation to start on alternative schedules, once conflicts that threaten the consistency of the database are detected. These ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....and unpredictable blocking times that damage its appeal for real time environments, where the primary performance criterion is meeting time constraints and not just preserving consistency requirements. Over the last few years, several alternatives to 2PL for RTDBMS have been proposed and explored [Kort90, Hari90a, Huan91, Kim91, Lin90, Son92]. Among these alternatives, the Optimistic Concurrency Control algorithm with Broadcast Commit (OCC BC) Mena82, Robi82] has been singled out as an attractive protocol for RTDBMS [Hari90b] In this paper, OCC BC is used as a representative of OCC based algorithms. In a recent study [Best92a] ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....(such as the possibility of deadlocks and or long, unpredictable blocking times) which damage its appeal for RTDBMS, where in addition to preserving database consistency, strict timing constraints must be honored. Recently, some alternatives to 2PL for real time systems have been proposed [Hari90b, Hari90a, Huan91, Kim91, Lin90, Son92]. A class of these concurrency control protocols is based on OCC, which due to its potential for a high degree of concurrency was expected to perform better than 2PL when integrated with priority driven CPU scheduling in real time database systems. In addition, the non blocking and deadlock free ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....(such as the possibility of deadlocks and or long, unpredictable blocking times) which damage its appeal for RTDBMS, where in addition to preserving database consistency, strict timing constraints must be honored. Recently, some alternatives to 2PL for real time systems have been proposed [Hari90b, Hari90a, Huan91, Kim91, Lin90, Son92]. A class of these concurrency control protocols is based on OCC, which due to its potential for a high degree of concurrency was expected to perform better than 2PL when integrated with priority driven CPU scheduling in real time database systems. In addition, the non blocking and deadlock free ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....2. 1 Survey, Initial Reading The following papers provide an exploration of the issues in real time database systems and introduce the research efforts in this area: Graham 1992] Kao Garcia Molina 1995] Ozsoyo glu Snodgrass 1995] Ramamritham 1993] Shu Young 1992] Singhal 1988] [Son et al. 1992c] Ulusoy 1992] Ulusoy 1995a] Yu et al. 1994] 2.2 Assignment of Timing Constraints Very few papers have been published so far regarding the sources and semantics of the timing constraints associated with real time database transactions: Kao Garcia Molina 1993a] Kao GarciaMolina ....

.... [Huang et al. 1992] Kim et al. 1990] Kim Srivastava 1991] Kuo Mok 1992] Lam et al. 1995] Lee Son 1993] Lee Son 1994] Lee Son 1995] Lin Son 1990] Sha et al. 1988] Sha et al. 1990] Sha et al. 1991] Son 1989] Son Chang 1990] Son Lee 1990] Son 1990] [Son et al. 1992a] Son et al. 1992b] Son et al. 1992d] Son et al. 1992e] Son Park 1993] Son Kouloumbis 1993] Tseng Chin 1993] Ulusoy Belford 1992] Ulusoy Belford 1993] Ulusoy Buchmann] Wolfe et al. 1990] 2.3.3 Commitment It is suggested in [Soparkar et al. 1992a] that the ....

[Article contains additional citation context not shown here]

S.H. Son, S. Park, Y.Lin `An Integrated Real-Time Locking Protocol', Proceedings of the 8th International Conference on Data Engineering, 1992, pp.527-534.

.... are used in conjunction with PCC based techniques [Abbo88, Agra87, Stan88, Huan89, Sing88, Sha88, Sha91] to make it possible for more urgent transactions to abort conflicting, less urgent ones (thus avoiding the hazards of blockages) and are used in conjunction with OCC based techniques [Kort90, Hari90b, Hari90a, Huan91, Kim91, Lin90, Son92] to favor more urgent transactions when conflicting, less urgent ones attempt to validate and commit (thus avoiding the hazards of restarts) In a recent study [Best92] we proposed a categorically different approach to concurrency control that combines the advantages of both OCC and PCC protocols ....

....T 2 V C Rx V C Blocked 0 0 1 Value D 1 A 1 D 2 A 2 t 1 t 2 v 1 v 2 a 1 a 2 o o (a) Time T 2 S Rx Time T 1 S Wx A T 2 V C Blocked 0 0 1 Value D 1 A 1 D 2 A 2 1 2 v 1 v 2 a 1 a 2 Delayed C o o F (b) Figure 10: Value added to the system (a) without deferment (b) with deferment. to those proposed in [Agra92, Hari90a, Son92]. Whenever a transaction shadow T o u (executing on behalf of transaction Tu ) finishes its execution, we evaluate if it is advantageous to defer T o u s commitment for a later point in time. Finding the best point in time to commit a finished shadow T o u is a very hard optimization problem, ....

S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering, Tempe, AZ, February 1992.

....also the fact that data read by a transaction must be valid when a transaction read them and must stay valid until completion of the transaction. These requirements make existing CCP for conventional DB unacceptable for RTDBS. Most of CCPs for RTDBS are extensions of protocols for conventional DB [8, 10, 9, 11], but no of them can guarantee the satisfaction of all timing requirements. 3 A Brief Summary of Duration Calculus In this section, we give a brief summary of Duration Calculus which will be used as the formalism to specify the models of DBS and RTDBS in this paper. For more details, readers are ....

S. H. Son, S. Park, and Y. Lin. An integrated real-time locking protocol. In Eighth IEEE International Conference on Data Engineering, pages 527--534, Phoenix, Arizona, February 1992.

....multiple levels of guarantees. Some of them assume process control systems having highly perishable data and hard deadline transactions as their target applications [13, 16, 3, 18] Others consider fullfledged information management systems supporting only soft or firm deadline transactions [1, 5, 6, 17]. In this paper, we present a scheme for transaction processing that supports various types of real time transactions with various levels of guarantees. We focus on two issues, predictability and consistency , which are fundamental to real time transaction processing, but sometimes require ....

....RTDBS can apply such an extended correctness criteria under various situations. 3 Real Time Database System Model Most real time database scheduling algorithms have been developed and evaluated under almost the same workload and operating environment model used in conventional database systems [1, 5, 6, 17]. That is, transactions are assumed to arrive in a Poisson stream at a specified mean rate, and each transaction consists of a random sequence of pages to be read, a subset of which are also updated. While this model is reasonable for some real time database applications with soft or firm ....

[Article contains additional citation context not shown here]

S. H. Son, S. Park, and Y. Lin. An Integrated RealTime Locking Protocol. In Proceedings of the 8th IEEE International Conference on Data Engineering, pages 527--534, Phoenix, AZ, February 1992.

No context found.

Son, S. H., S. Park, and Y. Lin, "An Integrated Real-Time Locking Protocol," IEEE Conference on Data Engineering, February 1992, pp. 527-534.

....applications and maintain consistency requirements of a real time database. 21.3 The Real Time Database Model Most real time database scheduling algorithms have been developed and evaluated under almost the same workload and operating environment model used in conventional database systems [1, 10, 12, 25]. That is, transactions are assumed to arrive in a Poisson stream at a specified mean rate. Each transaction consists of a random sequence of pages to be read, a subset of which are also updated. In addition, a conventional disk based database environment is assumed. The general approach is to ....

....available for some soft real time transactions and should be utilized to improve the system performance. However, we decide not to further categorize soft real time transactions but to concentrate on Class I and II transactions. Much work has been already done for this class of transactions [1, 10, 12, 25]. Moreover, all Class III transactions are supposed to have the same level of importance (noncritical) and not to require an individual performance guarantee. Non real time conventional transactions which do not have any timing constraints and access only discrete data objects also can be included ....

[Article contains additional citation context not shown here]

S. H. Son, S. Park, and Y. Lin. An Integrated Real-Time Locking Protocol. In Proceedings of the 8th IEEE International Conference on Data Engineering, pages 527--534, Phoenix, AZ, February 1992.

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Son, S., S. Park, and Y. Lin, "An Integrated Real-Time Locking Protocol", Proceedings of 8th International Conference on Data Engineering, Februrary 1992.

....a RTDBS may use different correctness criteria under different situations. 3 The Real Time Database Model Most real time database scheduling algorithms have been developed and evaluated under almost the same workload and operating environment model used in conventional database systems [1, 4, 5, 9]. That is, transactions are assumed to arrive in a Poisson stream at a specified mean rate. Each transaction consists of a random sequence of pages to be read, a subset of which are also updated. In addition, a conventional disk based database environment is assumed. The general approach is to ....

....conflicts among Type V and Type IV transactions can occur, appropriate resolution schemes are required. This classification is summarized in Table 1. Most real time database researches use the models which include only a subset of the above types (e.g. fType I, II, IIIg [3, 6, 10] or fType Vg [1, 4, 5, 9]) and never discriminate among transactions in the system. However, in practice, all kinds of transactions can coexist in one system. Let us consider a medical information system as an example: Type I transactions are transactions which update the dynamic physical status of a critical patient ....

S. H. Son, S. Park, and Y. Lin. An Integrated Real-Time Locking Protocol. In Proceedings of the 8th IEEE International Conference on Data Engineering, pages 527--534, Phoenix, AZ, February 1992.

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S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International Conference on Data Engineering,Tempe, AZ, February 1992.

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S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International ConferenceonDataEngineering,Tempe, AZ, February 1992.

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S. Son, S. Park, and Y. Lin. "An integrated real-time locking protocol." In Prooceedings of the IEEE International ConferenceonDataEngineering,Tempe, AZ, February 1992.

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S. H. Son, S. Park, Y. Lin `An Integrated Real-Time Locking Protocol', 8th International Conference on Data Engineering, pp.527-534, 1992.

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S. H. Son, S. Park, Y. Lin `An Integrated Real-Time Locking Protocol', 8th International Conference on Data Engineering, pp.527-534, 1992.

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