Cache Consistency Research Articles

Blockchain-Enabled On-Path Caching for Efficient and Reliable Content Delivery in Information-Centric Networks

As the demand for online content continues to grow, traditional Content Distribution Networks (CDNs) are facing significant challenges in terms of scalability and performance. Information-Centric Networking (ICN) is a promising new approach to content delivery that aims to address these issues by placing content at the center of the network architecture. One of the key features of ICNs is on-path caching, which allows content to be cached at intermediate routers along the path from the source to the destination. On-path caching in ICNs still faces some challenges, such as the scalability of the cache and the management of cache consistency. To address these challenges, this paper proposes several alternative caching schemes that can be integrated into ICNs using blockchain technology. These schemes include Bloom filters, content-based routing, and hybrid caching, which combine the advantages of off-path and on-path cachings. The proposed blockchain-enabled on-path caching mechanism ensures the integrity and authenticity of cached content, and smart contracts automate the caching process and incentivize caching nodes. To evaluate the performance of these caching alternatives, the authors conduct experiments using real-world datasets. The results show that on-path caching can significantly reduce network congestion and improve content delivery efficiency. The Bloom filter caching scheme achieved a cache hit rate of over 90% while reducing the cache size by up to 80% compared to traditional caching. The content-based routing scheme also achieved high cache hit rates while maintaining low latency.

Research on Cache Coherence Protocol Verification Method Based on Model Checking

This paper analyzes the underlying logic of the processor’s behavior level code. It proposes an automatic model construction and formal verification method for the cache consistency protocol with the aim of ensuring data consistency in the processor and the correctness of the cache function. The main idea of this method is to analyze the register transfer level (RTL) code directly at the module level and variable level, and extract the key modules and key variables according to the code information. Then, based on key variables, conditional behavior statements are retrieved from the code, and unnecessary statements are deleted. The model construction and simplification of related core states are completed automatically, while also simultaneously generating the attribute library to be verified, using “white list” as the construction strategy. Finally, complete cache consistency protocol verification is implemented in the model detector UPPAAL. Ultimately, this mechanism reduces the 142 state-transition path-guided global states of the cache module to be verified into 4 core functional states driven by consistency protocol implementation, effectively reducing the complexity of the formal model, and extracting 32 verification attributes into 6 verification attributes, reducing the verification time cost by 76.19%.

Stream Applications: A Consistent Active Management Approach for Multi-Core Cache

This paper proposes a novel method for managing cache consistency in multi-core systems when executing stream applications. The method involves arranging a mark cache for private data caches, which includes an optional integrality descriptor for shared reading and writing data states and shared data manipulation positions. The integrality descriptor identifies the current mode of operation for shared data in the private data cache. Additionally, the method utilizes a two-dimensional array register, referred to as the shared data manipulation position, with width N and depth M, where N distinguishes between different cache blocks and locking territories, while M corresponds to the number of cache blocks. This enables the identification of the cache capable or block corresponding to shared data during read and write operations. The proposed method offers simplicity, ease of operation, low hardware implementation cost, good extensibility, and strong configurability, ultimately improving system effectiveness.

An Effective Management Model for Data Caching in MANET Environment

A mobile ad-hoc (MANET) network has the main challenge to provide the needed data for the desired mobile nodes. An efficient on request routing protocol for MANET is Ad-hoc on-demand Distance Vector (AODV), which is based on two main methods: route discovery and route maintenance. Route discovery is the process used to detect a route to the destination from the packet source, while route maintenance is the process used to detect a link failure and repair it. Cooperative caching tends improving data availability in mobile ad-hoc networks, the coordination of cache discovery and cache management strategies is very significant in the cooperative caching of MANETs because requests for data and answers to requested data can be reduced simply due to interference, network congestion, or when a forwarding node is out of reach and the route breaks down. Cooperative cache management is much more complicated in cooperative caching because it also depends on neighbouring nodes to decide what to cache. In this paper, three algorithms were proposed: (1) a combination algorithm for cache admission control based on cache data and location of data to save space and reduce data redundancy, (2) a value-based policy for cache placement and replacement instead of the more common least recently used strategy, depending on metrics that describe cached items to increase the local cache hit ratio, and (3) a combined algorithm for cache consistency that includes time-to-live, pull, and push policies to enhance data availability and system scalability. The proposed algorithm implemented by the NS3 simulation program; which used to create a network using the AODV protocol in several parameters and achieve better system performance.

An Effective Management Model for Data Caching in MANET Environment

A mobile ad-hoc (MANET) network has the main challenge to provide the needed data for the desired mobile nodes. An efficient on request routing protocol for MANET is Ad-hoc on-demand Distance Vector (AODV), which is based on two main methods: route discovery and route maintenance. Route discovery is the process used to detect a route to the destination from the packet source, while route maintenance is the process used to detect a link failure and repair it. Cooperative caching tends improving data availability in mobile ad-hoc networks, the coordination of cache discovery and cache management strategies is very significant in the cooperative caching of MANETs because requests for data and answers to requested data can be reduced simply due to interference, network congestion, or when a forwarding node is out of reach and the route breaks down. Cooperative cache management is much more complicated in cooperative caching because it also depends on neighbouring nodes to decide what to cache. In this paper, three algorithms were proposed: (1) a combination algorithm for cache admission control based on cache data and location of data to save space and reduce data redundancy, (2) a value-based policy for cache placement and replacement instead of the more common least recently used strategy, depending on metrics that describe cached items to increase the local cache hit ratio, and (3) a combined algorithm for cache consistency that includes time-to-live, pull, and push policies to enhance data availability and system scalability. The proposed algorithm implemented by the NS3 simulation program; which used to create a network using the AODV protocol in several parameters and achieve better system performance.

Efficient Cache Consistency Management for Transient IoT Data in Content-Centric Networking

Since Internet of Things (IoT) communications can enjoy many advantages brought by content-centric networking (CCN) in nature, there is an increasing interest on their integration for better information retrieval and distribution. Nevertheless, different from the conventional multimedia traffic of which contents are hardly changed, IoT data are always transient and updated by their producers according to the actual situation. As a result, if without any effective countermeasures, outdated copies are inevitably stored by CCN routers and then distributed to the associated consumers, degrading both caching efficiency and user experience. In fact, most of related policies take little account of information freshness for cached contents, and how to tackle transient IoT data in CCN is still an ignored but crucial issue required for further explorations. Therefore, in this article, we propose an efficient popularity-based cache consistency management scheme, which aims to guarantee freshness of IoT data returned by on-path routers and avoid heavy signalling costs introduced at the same time. Extensive simulations were performed under both real-world scare-free and binary-tree topologies, and corresponding results have proved the efficiency of the proposed scheme in timely evictions of outdated IoT data stored by CCN in-network caching.

Providing Cache Consistency Guarantee for ICN-Based IoT Based on Push Mechanism

This paper develops POPCache (POpularity-aware Push-based Cache), a cache management strategy to support cache consistency in ICN-based IoT. Based on the proposed push mechanism, POPCache can proactively update the slated content to impose strong consistency while achieving low overhead, because POPCache relieves the heavy burden of nodes (which can be resource-constrained IoT devices) of maintaining extra information. POPCache makes caching decisions by jointly considering several determining factors. We use the theoretical study to analyze POPCache’s overhead. Moreover, we conduct simulations to compare POPCache with existing works; results show that POPCache improves cache consistency and achieves good cache and network performance.

Cache coherency controller for MESI protocol based on FPGA

In modern techniques of building processors, manufactures using more than one processor in the integrated circuit (chip) and each processor called a core. The new chips of processors called a multi-core processor. This new design makes the processors to work simultanously for more than one job or all the cores working in parallel for the same job. All cores are similar in their design, and each core has its own cache memory, while all cores shares the same main memory. So if one core requestes a block of data from main memory to its cache, there should be a protocol to declare the situation of this block in the main memory and other cores.This is called the cache coherency or cache consistency of multi-core. In this paper a special circuit is designed using very high speed integrated circuit hardware description language (VHDL) coding and implemented using ISE Xilinx software. The protocol used in this design is the modified, exclusive, shared and invalid (MESI) protocol. Test results were taken by using test bench, and showed all the states of the protocol are working correctly.

MESI protocol for multicore processors based on FPGA

In modern techniques of building processors, manufactures using more than one processor in the integrated circuit (chip) and each processor called a core. The new chips of processors called a multi-core processor. This new design makes the processors to work simultaneously for more than one task or all the cores working in parallel for the same task. All cores are similar in their design, and each core has its own cache memory, while all cores shares the same main memory. So, if one core requests a block of data from main memory to its cache, there should be a protocol to declare the situation of this block in the main memory and other cores. This is called the cache coherency or cache consistency of multi-core. In this paper a special circuit is designed using VHDL coding and implemented using ISE Xilinx software, one protocol was used in this design, the MESI (Modify, Exclusive, Shared and Invalid) protocol. Test results were taken by using test bench, and showed all the states of the protocols are working correctly.

MESI protocol for multicore processors based on FPGA

In modern techniques of building processors, manufactures using more than one processor in the integrated circuit (chip) and each processor called a core. The new chips of processors called a multi-core processor. This new design makes the processors to work simultaneously for more than one task or all the cores working in parallel for the same task. All cores are similar in their design, and each core has its own cache memory, while all cores shares the same main memory. So, if one core requests a block of data from main memory to its cache, there should be a protocol to declare the situation of this block in the main memory and other cores. This is called the cache coherency or cache consistency of multi-core. In this paper a special circuit is designed using VHDL coding and implemented using ISE Xilinx software, one protocol was used in this design, the MESI (Modify, Exclusive, Shared and Invalid) protocol. Test results were taken by using test bench, and showed all the states of the protocols are working correctly.

Parallelizing Shared File I/O Operations of NVM File System for Manycore Servers

NOVA, a state-of-the-art non-volatile memory (NVM) file system, has limited performance due to its coarse-grained per-file lock when multiple threads perform I/Os to a shared file in a manycore environment. For instance, a writer lock blocks other threads attempting to access the same file, although they access different regions of a file. When multiple threads reading the same file share a cache line containing a reader counter, performance can be significantly degraded due to cache consistency protocol as we increase the number of readers. This paper proposes a fine-grained segment-based range lock (SRL) that divides a file into multiple segments and manages a lock variable dynamically for each segment. Consequently, write operations can be parallelized without blocking unless there is a conflict in accessing the same range in a file. Moreover, SRL maintains a reader counter per segment that allows multiple reader threads to perform read operations without causing a performance bottleneck. We evaluated an SRL-based NOVA on an Intel Optane DC persistent memory (PM) manycore server. The benchmarking results showed that the average write throughput of the SRL-based NOVA is $3\times $ higher than the original NOVA, and the average read throughput scales linearly, while the original NOVA does not scale.

Cloudburst

Function-as-a-Service (FaaS) platforms and "serverless" cloud computing are becoming increasingly popular due to ease-of-use and operational simplicity. Current FaaS offerings are targeted at stateless functions that do minimal I/O and communication. We argue that the benefits of serverless computing can be extended to a broader range of applications and algorithms while maintaining the key benefits of existing FaaS offerings. We present the design and implementation of Cloudburst, a stateful FaaS platform that provides familiar Python programming with low-latency mutable state and communication, while maintaining the autoscaling benefits of serverless computing. Cloudburst accomplishes this by leveraging Anna, an autoscaling key-value store, for state sharing and overlay routing combined with mutable caches co-located with function executors for data locality. Performant cache consistency emerges as a key challenge in this architecture. To this end, Cloudburst provides a combination of lattice-encapsulated state and new definitions and protocols for distributed session consistency. Empirical results on benchmarks and diverse applications show that Cloudburst makes stateful functions practical, reducing the state-management overheads of current FaaS platforms by orders of magnitude while also improving the state of the art in serverless consistency.

RSCVC: Row‐based semantic cache with incremental versioning consistency

SummaryIn the mobile computing environment, how to make the data access more efficient is a challenge due to the narrow communication bandwidth, the frequent disconnections of network, and the limited resources. Therefore, it is necessary to cache data on the client side. Besides, a good cache consistency method is essential to ensure the correctness. In this article, a row‐based semantic cache with incremental versioning consistency (RSCVC) is proposed. In RSCVC, we designed a semantic cache algorithm, a query trimming and optimizing algorithm, and a version‐based consistency strategy. This RSCVC cache mainly has two advantages. On one hand, it can obviously improve the response time of query and the hit ratio of the cache. On the other hand, the version‐based consistency enhances the stability of the system especially in high‐concurrency situations. Experiments demonstrate the efficacy of our proposed method and its superiority to state‐of‐the‐art methods.

A Cache Invalidation Strategy Based on Publish/Subscribe for Named Data Networking

Named Data Networking (NDN) aims to improve the efficiency of data delivery for the Internet. One of the typical characteristics of NDN is ubiquitous caching, that is to say, each network participant in NDN is capable of caching contents. This caching feature is beneficial for enhancing the data availability but also raises a problem of cache consistency. In this paper, we propose a novel strategy of cache invalidation, called PIOR (Proactive Invalidation with Optional Renewing), to provide strong consistency for NDN. PIOR is based on a lightweight publish/subscribe model, actively publishing the updated contents to the router nodes to guarantee the copy validity. We also conceive customized publish/subscribe rules to relieve the unbearable burden on the server imposed by the excessive publishing traffic. The advantage of PIOR lies in simple deployment and compatibility, since the invalidation process of PIOR is independent of the inherent process of NDN. We conduct extensive simulations over a real topology to evaluate the achievable performance of PIOR. The simulation results show that PIOR is able to achieve a high hit ratio and low server load at the low cost of network management.

Fine Granularity and Adaptive Cache Update Mechanism for Client Caching

Distributed file systems have been commonly used as the back end to provide high-performance I/O services for hosting complicated data processing, such as database workloads. By buffering the frequently used data in the local file cache, which is called the client caching mechanism, can reduce the I/O latency and improve the performance of file access. However, the overhead and complexity for ensuring data consistency may offset the performance benefits caused by data caching. This paper proposes an adaptive, per-block cache update mechanism, which can ensure data consistency of block data in a distributed file system, with low synchronization overhead. Specifically, based on the recent history of read/write requests, the proposed scheme can adaptively select the best-suited consistency update policy for each data block at run time. The experiments on database applications show that our newly proposed mechanism can greatly reduce the overhead resulted by maintaining cache consistency, especially for the workloads having fluctuating read/write ratios. As a consequence, the system performance can be also enhanced.

Effective E-Healthcare System

Focus of health care data research has shifted towards configuring and handling e-health information from heterogeneous e-health administration entities in a Content Distribution Network (CDN) for gaining e-health benefits which may be a testing errand. In recent trends, CDNis typically is used to reserve e-health networking substance as ongoing images captured in real time sequences and ongoing videos. In mobile cloud computing, due to patient's movement, it is required for medicinal services professionals to bring information of patient health with quick access of e-health data to make effective choices and select medication. Caching and its invalidation mechanism will provide the solutions in effective e-health data availability. A lot of caching methodologies are proposed, such as the Scalable Asynchronous Cache Consistency Scheme (SACCS) which has demonstrated more versatility over others. In this article, the authors recommend another reserve reinstatement algorithm with SACCS in consideration that is dependent upon rule-based Least Profit Value.

Enhanced Service Discovery Protocol for MANET by Effective Cache Management

With the increasing pervasiveness of the mobile nodes, service discovery has become inevitable. In the resource constrained mobile nodes, caching is being used to reduce the access cost. The enhanced service discovery protocol presented in this paper is a combination of cache placement, cache discovery, cache consistency and replacement algorithms. The overheard service information is cached by the coordinator nodes of each geographical area to reduce the discovery delay. A light weight cache discovery algorithm that uses a minimum spanning tree is proposed. The cache consistency is maintained in a soft state. Cache replacement is done based on a weight value that is calculated using the recency, frequency and cost factors. An M/G/1/∞ non-preemptive queuing model is proposed to analyse the cache replacement performance. The extensive simulation results performed to demonstrate the effectiveness of the proposed enhanced service discovery protocol in terms of reduction in the service discovery delay and number of cache replacements. The replacement scheme proposed has increased the cache hit ratio.

Three levels of fail-safe mode in MPI I/O NVRAM distributed cache

The paper presents architecture and design of three versions for fail-safe data storage in a distributed cache using NVRAM in cluster nodes. In the first one, cache consistency is assured through additional buffering write requests. The second one is based on additional write log managers running on different nodes. The third one benefits from synchronization with a Parallel File System (PFS) for saving data into a new file which allows to keep file history at the cost of space. We have shown that the three level fail-safe mode incorporating these versions does introduce minimal overhead for a random walk microbenchmark application for a 1GB file and checkpoints created every 2000 iterations, computing powers of a graph with 10000 vertices and up to 20% overhead for parallel processing of images up to 1000 megapixels compared to the basic NVRAM cache without fail-safe modes. We also presented times for checkpoint creation and restoring for sizes up to 10GBs.

A Cache Consistency Protocol with Improved Architecture

A Cache Consistency Protocol with Improved Architecture

Adaptive Hybrid Methods for Cooperative Caching Consistency in Mobile Ad-Hoc Networks

Adaptive Hybrid Methods for Cooperative Caching Consistency in Mobile Ad-Hoc Networks