File Replication

Cloud Computing makes immense use of internet to store a huge amount of data. Cloud computing provides high quality service with low cost and scalability with less requirement of hardware and software management. Security plays a vital role in cloud as data is handled by third party hence security is the biggest concern to matter. This proposed mechanism focuses on the security issues on the cloud. As the file is stored at a particular location which might get affected due to attack and will lost the data. So, in this proposed work instead of storing a complete file at a particular location, the file is divided into fragments and each fragment is stored at various locations. Fragments are more secured by providing the hash key to each fragment. This mechanism will not reveal all the information regarding a particular file even after successful attack. Here, the replication of fragments is also generated with strong authentication process using key generation. The auto update of a fr...

Cloud Computing makes immense use of internet to store a huge amount of data. Cloud computing provides high quality service with low cost and scalability with less requirement of hardware and software management. Security plays a vital role in cloud as data is handled by third party hence security is the biggest concern to matter. This proposed mechanism focuses on the security issues on the cloud. As the file is stored at a particular location which might get affected due to attack and will lost the data. So, in this proposed work instead of storing a complete file at a particular location, the file is divided into fragments and each fragment is stored at various locations. Fragments are more secured by providing the hash key to each fragment. This mechanism will not reveal all the information regarding a particular file even after successful attack. Here, the replication of fragments is also generated with strong authentication process using key generation. The auto update of a fr...

A distributed system is collection of computer nodes or devices that area unit geographically distributed and connected through a communication link. Security can be defined as "A state of phenomenon which gives guarantee of accomplishment with full trust and reliability to users." This works concludes that lack of security measures or zero security may give open opportunity for security attacks and create fear in user mind. It may become very crucial issue when communication performs through public channel or networks. Replication is that the method of making and managing duplicate versions of a information or file or content to take care of backup or duplicate copy of original one. Replication not solely copies a information however conjointly synchronizes a collection of reproductions in order that changes created to one replica area unit mirrored altogether the others. Security is one of important phenomena to maintain trust of user and privacy on content. This paper observes this issue and rectifies the need to improve the privacy factor during replication. The complete works conclude a requirement of secure replication to manage work distribution properly. A integrity maintenance and confidentiality management can help to achieve security during replication.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost, and average query delay.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost, and average query delay.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost, and average query delay.

Cloud computing makes immense use of internet to store a huge amount of data. Cloud computing provides high quality service with low cost and scalability with less requirement of hardware and software management. Security plays a vital role in cloud as data is handled by third party hence security is the biggest concern to matter. This proposed mechanism focuses on the security issues on the cloud. As the file is stored at a particular location which might get affected due to attack and will lost the data. So, in this proposed work instead of storing a complete file at a particular location, the file is divided into fragments and each fragment is stored at various locations. Fragments are more secured by providing the hash key to each fragment. This mechanism will not reveal all the information regarding a particular file even after successful attack. Here, the replication of fragments is also generated with strong authentication process using key generation. The auto update of a fragment or any file is also done here. The concept of auto update of files is done where a file or a fragment can be updated online. Instead of downloading the whole file, a fragment can be downloaded to update. More time is saved using this methodology.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multi hop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of data accessibility, communication cost, and average query delay.

We recently showed for peer-to-peer networks, that having the number of replicas of each object proportional to the request rate for these objects has many per-node advantages. In this paper we complement those results to show that this distribution has network-wide advantages as well. Given these benefits of proportional replication, the next issue is achieving proportional replication in a decentralized manner. We show that local storage management algorithms like LRU automatically achieve near-proportional replication and that the system performance with the replica distribution achieved by LRU is very close to optimal. We also show that the LRU responds to a change in user access pattern quickly (the number of accesses taken to reach the new steady-state replica distribution with LRU is close to the minimum possible with any cache replacement algorithm). Analytical models are provided for computing the steady-state network-wide replica distribution and the transient period for LRU.

We recently showed for peer-to-peer networks, that having the number of replicas of each object proportional to the request rate for these objects has many per-node advantages. In this paper we complement those results to show that this distribution has network-wide advantages as well. Given these benefits of proportional replication, the next issue is achieving proportional replication in a decentralized manner. We show that local storage management algorithms like LRU automatically achieve near-proportional replication and that the system performance with the replica distribution achieved by LRU is very close to optimal. We also show that the LRU responds to a change in user access pattern quickly (the number of accesses taken to reach the new steady-state replica distribution with LRU is close to the minimum possible with any cache replacement algorithm). Analytical models are provided for computing the steady-state network-wide replica distribution and the transient period for LRU.

In a Mobile Ad hoc Network (MANET), due to mobility, limited battery power and poor features of nodes, network partitioning and nodes disconnecting occur frequently. To improve data availability, database systems create multiple copies of each data object and allocate them on different nodes. This paper proposes Automated Re-allocator of Replicas Over MANET (ARROM), that addresses these issues. ARROM reduces the average response time of requests between clients and database servers by reallocating replicas frequently. In addition, ARROM increases the average throughput in the network. Our performance study indicates that ARROM improves average response time and average network throughput in MANET as compared to resent existing scheme.

File sharing applications in mobile ad hoc networks (MANETs) have attracted more and more attention in recent years. The efficiency of file querying suffers from the distinctive properties of such networks including node mobility and limited communication range and resource. An intuitive method to alleviate this problem is to create file replicas in the network. However, despite the efforts on file replication, no research has focused on the global optimal replica creation with minimum average querying delay. Specifically, current file replication protocols in mobile ad hoc networks have two shortcomings. First, they lack a rule to allocate limited resource to different files in order to minimize the average querying delay. Second, they simply consider storage as resource for replicas, but neglect the fact that the file holders' frequency of meeting other nodes also plays an important role in determining file availability. Actually, a node that has a higher meeting frequency with others provides higher availability to its files. This becomes even more evident in sparsely distributed MANETs, where nodes meet disruptively. In this paper, we introduce a new concept of resource for file replication, which considers both node storage and meeting frequency. We theoretically study the influence of resource allocation on the average querying delay and derive a resource allocation rule to minimize the average querying delay. We further propose a distributed file replication protocol to realize the proposed rule. Extensive trace-driven experiments with synthesized traces and real traces show that our protocol can achieve shorter average querying delay at a lower cost than current replication protocols.

In MANETs some of the nodes do not take part in forwarding packets to other nodes to conserve their resources such as energy, bandwidth and power. The nodes which act selfishly to conserve their resources are called selfish nodes. The selfish nodes are engaged to reduce data availability and produce high communication cost in terms of query processing. Many selfish node detection methods are found to detect the nodes which do not participate in packet forwarding but they fail to detect the selfish nodes which does not allocate replica for the purpose of other nodes. This survey paper provides methods to detect selfish nodes in terms of allocating replica to other nodes. The methods are categorised according to detect the selfish nodes and reduce the impact of that nodes in mobile ad hoc network. It also discusses the key features of selfish nodes and numerous replica allocation techniques. The introduction of new replica allocation techniques will considerably reduce the delay in qu...

ABSTARCT The nodes in Mobile Ad Hoc Network are resource constrained. This drawback and mobility nature of nodes can cause network partitioning and degradation of performance. Traditionally replica allocation techniques were used to overcome the drawback of performance degradation. It is assumed that all nodes in MANET share their memory resources fully. However, in reality the nodes may behave selfishly instead of cooperating in communication process. The selfishness exhibited by some of the nodes may lead to reduced quality of data accessibility over network. Recently Choi et al. studied the impact of selfish nodes from replication allocation perspective. Their solution is named “Selfish Replica Allocation”. They proposed a novel replica allocation and selfish node detection. In this paper we implemented those mechanisms for casting selfish nodes in non selfish from the perspective of replica allocation. We built a custom Java simulator to demonstrate the proof of concept. The emp...

This paper presents an intelligent mechanism for a vehicular micro cloud (i.e., a cluster of connected vehicles) to form a regional distributed data storage over V2V networks. Each member vehicle keeps a subset of data contents in their local data storage device, and hands over the contents to other member(s) when leaving the vehicular micro cloud. In order to cope with potential data loss due to failure of content handovers, the vehicular micro cloud creates replica(s) of each data content, and keeps them at different member vehicles. However, even if the system creates multiple replicas, there still remains the risk of losing all of them at once, as vehicles hosting the replicas could move away from the vehicular micro cloud in a short period of time. Such simultaneous failures could frequently occur, since vehicles in the vicinity often have strong correlation in their mobility. To address this issue, our algorithm assigns data replicas to a small subset of member vehicles, whose...

Wireless networks can be infrastructure based or infrastructureless. An infrastructureless network having large number of mobile nodes, which can fulfill a wireless interconnection, can be called as a MANET. The MANET nodes should be aware of the data stored in them. No MANET communication should be a failure due to the problem of inaccessibility of data packets. In the past, many people have worked on this problem, and developed the idea of replicating data items to minimize this data inaccessibility. The process can be called as replica allocation. This paper provides a comparison between different techniques used to increase data accessibility in MANETs. Attacker nodes like selfish nodes will generate a situation of imperfect replica allocation, commonly referred to as selfish replica allocation. The problem of selfish replica allocation will not allow the network nodes to allocate replica effectively. A selfish network shows much less packet delivery ratio, in comparison with a non-selfish network. Among the replica allocation methods considered, the SCF-tree based replica allocation method eliminates the overall selfishness in the network; and excels in providing maximum data accessibility compared to the other methods.

We introduce a novel file replication model is optimizations reacting to changes in the patterns of access to the file system by dynamically creating or deleting replicas. Replication is used to improve data availability in the presence of site failures and to decrease retrieval costs by local access is possible. Mobile Ad hoc Networks (MANET) take collection of wireless mobile system dynamically forming new network without the use of any backend infrastructure or centralized administration. Based on Peer-to-Peer (P2P) network file destitute is mainly implementing in MANET. Several data replication protocol is proposed to minimize results degradation. We introduce a new concept of Distributed File Replication algorithm which considers file dynamics network such as file addition and deletion in dynamic manner. Content-based file sharing scheme using dynamic network is proposed user interest is determined by the proposed scheme before searching and sharing the files in the peer-to-peer network. It provide security to decentralized p2p network by the implementation of key server and Intrusion Detection System (IDS) with new P2PHBA algorithm is used for the prediction modify path in the network by the scout is implementation to the efficient file sharing. The present replication protocol is drawbacks, they are node storage and the allocation of resources in the replications Future wireless communications are heading many all-Internet Protocol (all-IP) design and will rely on the Session Initiation Protocol (SIP) to manage services such as voice over IP (VoIP).

In a Mobile Ad hoc Network (MANET), due to mobility, limited battery power and poor features of nodes, network partitioning and nodes disconnecting occur frequently. To improve data availability, database systems create multiple copies of each data object and allocate them on different nodes. This paper proposes Automated Re-allocator of Replicas Over MANET (ARROM), that addresses these issues. ARROM reduces the average response time of requests between clients and database servers by reallocating replicas frequently. In addition, ARROM increases the average throughput in the network. Our performance study indicates that ARROM improves average response time and average network throughput in MANET as compared to resent existing scheme.

In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. In particular, we develop a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. Network partitions can occur frequently, since nodes move freely in a MANET, causing some data to be often inaccessible to some of the nodes. Hence, data accessibility is often an important performance metric in a MANET. Data are usually replicated at nodes, other than the original owners, to increase data accessibility to cope with frequent network partitions. A considerable amount of research has recently been proposed for replica allocation in a MANET. In general, replication can simultaneously improve data accessibility and reduce query delay, i.e., query response time, if the mobile nodes in a MANET together have sufficient memory space to hold both all the replicas and the original data.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multihop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. The resource and mobility constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. Due to such problem the overall process of MANET got affected. In this work, first examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. This is known as selfish replica allocation.The selfish replica allocation could lead to overall poor data accessibility in a MANET. The proposed selfish node detection method and novel replica allocation techniques to handle the selfish replica allocation appropriately. The proposed strategies are inspired by the real-world observations in economics in terms of credit risk and in human friendship management in terms of choosing one's friends completely at one's own discretion,and applied the notion of credit risk from economics to detect selfish nodes. Every node in a MANET calculates credit risk information on other connected nodes individually to measure the degree of selfishness.

MOBILE ad hoc networks (MANETs) have attracted a lot of attention due to the popularity of mobile devices and the advances in wireless communication technologies. A MANET is a peer-to-peer multihop mobile wireless network that has neither a fixed infrastructure nor a central server. Each node in a MANET acts as a router, and communicates with each other. The resource and mobility constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. Due to such problem the overall process of MANET got affected. In this work, first examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. This is known as selfish replica allocation.The selfish replica allocation could lead to overall poor data accessibility in a MANET. The proposed selfish node detection method and novel replica allocation techniques to handle the selfish replica allocation appropriately. The proposed strategies are inspired by the real-world observations in economics in terms of credit risk and in human friendship management in terms of choosing one's friends completely at one's own discretion,and applied the notion of credit risk from economics to detect selfish nodes. Every node in a MANET calculates credit risk information on other connected nodes individually to measure the degree of selfishness.

in wireless ad hoc networks, all nodes cooperate to provide network services. Due to the limited radio transmission range, data packets are usually forwarded through multiple relay nodes before they reach the destinations. If a node always serves as a relay to transmit the packets, it may quickly use up its own energy and other resources. Therefore, some nodes use a selfish approach, they try to avoid forwarding the packets. Such selfish behavior would probably cause the network to break down. Selfish nodes are common within ad hoc networks because they are managed by different resources. The performance of ad-hoc network degraded because of selfish node which causes large packet loss, low throughput, decrease data accessibility, high query delay, high communication cost, higher chances for network cresses etc. In a mobile ad hoc network, the mobility and resource constraints of mobile nodes may lead to network partitioning or performance degradation. Several data replication techniques have been proposed to minimize performance degradation. Most of them assume that all mobile nodes collaborate fully in terms of sharing their memory space. In reality, however, some nodes may selfishly decide only to cooperate partially, or not at all, with other nodes. These selfish nodes could then reduce the overall data accessibility in the network. In this paper, we examine the impact of selfish nodes in a mobile ad hoc network from the perspective of replica allocation. We term this selfish replica allocation. In particular, we use a selfish node detection algorithm that considers partial selfishness and novel replica allocation techniques to properly cope with selfish replica allocation. The conducted simulations demonstrate the proposed approach outperforms traditional cooperative replica allocation techniques in terms of communication cost, throughput, packet delay and packet delivery ratio.