Distributed Caching System Research Articles

Design and Implementation of Distributed Cache System in Cluster Environment

Within the layered enterprise application architecture, database is usually the bottleneck of system. Cache technology can significantly improve the system performance and scalability by caching the data in application layer. Firstly, this paper discussed the significance and importance of the Distributed Cache System. Our system provided two kinds of cache mechanism, including replicated cache and partitioned cache. Each of these has advantages and disadvantages. The design and implementation of this system covered problems including consistent hashing arithmetic. This paper described and analyzed data distribution, data update and the procedure of operations in different cache mechanisms. At last, we made the compared test between our system and the similar product, Memcached. We found that there are both advantages and disadvantages of these two products, it points out the direction for our future improvement.

A replacement strategy for a distributed caching system based on the spatiotemporal access pattern of geospatial data

Abstract. Cache replacement strategy is the core for a distributed high-speed caching system, and effects the cache hit rate and utilization of a limited cache space directly. Many reports show that there are temporal and spatial local changes in access patterns of geospatial data, and there are popular hot spots which change over time. Therefore, the key issue for cache replacement strategy for geospatial data is to get a combination method which considers both temporal local changes and spatial local changes in access patterns, and balance the relationship between the changes. And the cache replacement strategy should fit the distribution and changes of hotspot. This paper proposes a cache replacement strategy based on access pattern which have access spatiotemporal localities. Firstly, the strategy builds a method to express the access frequency and the time interval for geospatial data access based on a least-recently-used replacement (LRU) algorithm and its data structure; secondly, considering both the spatial correlation between geospatial data access and the caching location for geospatial data, it builds access sequences based on a LRU stack, which reflect the spatiotemporal locality changes in access pattern. Finally, for achieving the aim of balancing the temporal locality and spatial locality changes in access patterns, the strategy chooses the replacement objects based on the length of access sequences and the cost of caching resource consumption. Experimental results reveal that the proposed cache replacement strategy is able to improve the cache hit rate while achieving a good response performance and higher system throughput. Therefore, it can be applied to handle the intensity of networked GISs data access requests in a cloud-based environment.

Toward a scale-out data-management middleware for low-latency enterprise computing

Emerging transactional workloads from Internet and mobile commerce require low-latency, massive-scale, and integrated data analytics to enhance user experience and to improve up-selling opportunities. These analytics require new application platforms that must be able to absorb large volumes of data, provide low-latency access to the data, and cache data objects to improve access times in distributed environments. This paper reports on recent technologies built at IBM Research to address challenges in data access latency, data ingestion, and caching in the exemplary context of an online product recommendation application. We describe three technologies related to the issues and optimizations of key-value data object store and access. First, we describe the architecture of a global secondary index to greatly improve data access latency of Hadoop™ Database (HBase™), an open-source key-value distributed data store. Second, we present an in-memory write-ahead log feature on HBase that significantly improves write operations for high-volume data ingestion. Third, we detail an innovative distributed caching system that exploits low-latency interconnects to use hash maps of data keys on each server for local lookup, while data resides and are accessed across clustered systems. The distributed cache can achieve a 100-to 1,000-fold performance gain over many caching methods. These technologies together form some necessary building blocks for a next-generation data-centric middleware for integrated transaction and analytic workloads.

Balanced partition scheme for distributed caching systems to solve load imbalance problems

Distributed caching system is usually used to alleviate database load in constructing an enterprise web application system. It helps to speed up dynamic web applications. In order to improve the utilization of caching cluster, an appropriate data partitioning and placement scheme is usually applied. This paper proposes a Balanced Partition Scheme (BPS) to solve load imbalance problems and highly skewed data requests in web application. In the BPS, which is based on consistent hash algorithm, the partition and placement schemes are designed respectively to guarantee a system's load balance even when the requests of this system are highly skewed. The range of hash function is divided into several groups equally and those groups will be relocated when caching nodes are overloaded. The implementation and evaluation of the BPS is also presented in this paper. The effectiveness of the BPS has been verified in the simulation experiment and the BPS can successfully solve load imbalance problems when faced with a large number of get/set requests.

A Dynamic Programming Algorithm for QoS-aware Replica Placement in Distributed Caching Systems

A Dynamic Programming Algorithm for QoS-aware Replica Placement in Distributed Caching Systems

Area-based collaborative distributed cache system using consumer electronics mobile device

New communication services among nearby passing people are growing rapidly thanks to the advance of short-range wireless communication technologies and the widespread use of mobile devices that use them. Time-offset communication capability will engender a new service paradigm and promote new service emergence. This paper presents a proposal of a new distributed mobile cache system to cache data temporarily in a designated local area. The system is realized through collaborative consumer electronics mobile devices which use no infrastructure network. The system overview and its middleware on the mobile devices are explained. Furthermore, new relay data algorithms are proposed to provide lower-overhead communication and a more robust caching capability. Finally, results of simulation experiments underscore the effectiveness of the proposed control algorithm in terms of the communication cost and the length of the cache time.

Semantics-Based Object Caching in Distributed Systems

In order to utilize the semantics of object methods to ensure cached object consistency, method group commutativity specifies the conditions under which a group of methods will commute. Method group commutativity is determined using a semantic specification of object methods, provided in terms of logical expressions, to create commutativity conjectures that are analyzed using the PVS theorem prover. This analysis results in the creation of a method commutativity specification (MCS), which is used by a distributed caching system to ensure the consistency of method invocations. For greater commutativity, weaker consistency requirements can be specified in the MCS. This base approach is enhanced by optimizations that consider a client's sequential execution of methods and that reduce the amount of data cached by the client. The effectiveness of method group commutativity and associated optimizations is evaluated using Java RMI application benchmarks.

A Coherence-Replacement Protocol For Web Proxy Cache Systems

As World Wide Web usage has grown dramatically in recent years, so has the recognition that web caches (especially proxy caches) will have an important role in reducing server loads, client request latencies, and network traffic. In this paper, we propose an adaptive cache coherence-replacement scheme for web proxy cache systems that is based on several criteria about the system and applications, with the objective of optimizing the distributed cache system performance. Our coherence-replacement scheme assigns a replacement priority value to each cache block according to a set of criteria for deciding which block to remove. The goal is to provide an effective utilization of the distributed cache memory and a good application performance.