QoS Measures for Orchestrations in Unreliable Environments

When dealing with Grid applications, there could append a lot of different thinks that could make the final execution differ some times. For example, is over-optimistic to suppose that all the site calls that the Grid application management system does to perform sub-computations are operatives the 100% of the time and no error never happens. Another case, for example is when the final result varies depending on the values returned by the services. When the user accepts this non-determinism, it may be good to give some estimation of success. Here we will see some approaches to this problem based on the Expected number of published values and the Probability of failure on non-recursive Orc expressions describing the orchestration of sites in Grid applications. We will see that in some cases those problems are only tractable under certain conditions and the special case created by the delay of site calls when there are no restrictions on the Orc expressions. After that, a new approach based on the probability of delays will be presented. With this approach we will give a new estimations based on the average time required for values to be published and the time required to publish the first or last value. As an annex, a Java library to compute some of those problems is given and some important points will be seen

The computational complexity of QoS measures for orchestrations

The final publication is available at link.springer.comWe consider Web services defined by orchestrations in the Orc language and two natural quality of services measures, the number of outputs and a discrete version of the first response time. We analyse first those subfamilies of finite orchestrations in which the measures are well defined and consider their evaluation in both reliable and probabilistic unreliable environments. On those subfamilies in which the QoS measures are well defined, we consider a set of natural related problems and analyse its computational complexity. In general our results show a clear picture of the difficulty of computing the proposed QoS measures with respect to the expressiveness of the subfamilies of Orc. Only in few cases the problems are solvable in polynomial time pointing out the computational difficulty of evaluating QoS measures even in simplified models.Peer ReviewedPostprint (author's final draft

Scalable topological forwarding and routing policies in RINA-enabled programmable data centers

This is the peer reviewed version of the following article: Leon Gaixas S, Perelló J, Careglio D, Grasa E, López DR, Aranda PA. Scalable topological forwarding and routing policies in RINA-enabled programmable data centers. Trans Emerging Tel Tech. 2017;28:e3256, DOI 10.1002/ett.3256, which has been published in final form at DOI: 10.1002/ett.3256. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingGiven the current expansion of cloud computing, the expected advent of the Internet of Things, and the requirements of future fifth-generation network infrastructures, significantly larger pools of computational and storage resources will soon be required. This emphasizes the need for more scalable data centers that are capable of providing such an amount of resources in a cost-effective way. A quick look into today's commercial data centers shows that they tend to rely on variations of well-defined leaf-spine/Clos data center network (DCN) topologies, offering low latency, ultrahigh bisectional bandwidth, and enhanced reliability against concurrent failures. However, DCNs are typically restricted by the use of the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, thus suffering limited routing scalability. In this work, we study the benefits that replacing TCP/IP with the recursive internetwork architecture (RINA) can bring into commercial DCNs, focusing on forwarding and routing scalability. We quantitatively evaluate the benefits that RINA solutions can yield against those based on TCP/IP and highlight how, by deploying RINA, topological routing solutions can improve even more the efficiency of the network. To this goal, we propose a rule-and-exception forwarding policy tailored to the characteristics of several DCN variants, enabling fast forwarding decisions with merely neighbors' information. Upon failures, few exceptions are necessary, whose computation can also profit from the known topology. Extensive numerical results show that the proposed policy requirements depend mainly on the number of neighbors and concurrent failures in the DCN rather than its size, dramatically reducing the amount of forwarding and routing information stored at DCN nodes.Peer ReviewedPostprint (author's final draft

QoS Measures for Orchestrations in Unreliable Environments

When dealing with Grid applications, there could append a lot of different thinks that could make the final execution differ some times. For example, is over-optimistic to suppose that all the site calls that the Grid application management system does to perform sub-computations are operatives the 100% of the time and no error never happens. Another case, for example is when the final result varies depending on the values returned by the services. When the user accepts this non-determinism, it may be good to give some estimation of success. Here we will see some approaches to this problem based on the Expected number of published values and the Probability of failure on non-recursive Orc expressions describing the orchestration of sites in Grid applications. We will see that in some cases those problems are only tractable under certain conditions and the special case created by the delay of site calls when there are no restrictions on the Orc expressions. After that, a new approach based on the probability of delays will be presented. With this approach we will give a new estimations based on the average time required for values to be published and the time required to publish the first or last value. As an annex, a Java library to compute some of those problems is given and some important points will be seen

QoS Measures for Orchestrations in Unreliable Environments

When dealing with Grid applications, there could append a lot of different thinks that could make the final execution differ some times. For example, is over-optimistic to suppose that all the site calls that the Grid application management system does to perform sub-computations are operatives the 100% of the time and no error never happens. Another case, for example is when the final result varies depending on the values returned by the services. When the user accepts this non-determinism, it may be good to give some estimation of success. Here we will see some approaches to this problem based on the Expected number of published values and the Probability of failure on non-recursive Orc expressions describing the orchestration of sites in Grid applications. We will see that in some cases those problems are only tractable under certain conditions and the special case created by the delay of site calls when there are no restrictions on the Orc expressions. After that, a new approach based on the probability of delays will be presented. With this approach we will give a new estimations based on the average time required for values to be published and the time required to publish the first or last value. As an annex, a Java library to compute some of those problems is given and some important points will be seen

The computational complexity of QoS measures for orchestrations

The final publication is available at link.springer.comWe consider Web services defined by orchestrations in the Orc language and two natural quality of services measures, the number of outputs and a discrete version of the first response time. We analyse first those subfamilies of finite orchestrations in which the measures are well defined and consider their evaluation in both reliable and probabilistic unreliable environments. On those subfamilies in which the QoS measures are well defined, we consider a set of natural related problems and analyse its computational complexity. In general our results show a clear picture of the difficulty of computing the proposed QoS measures with respect to the expressiveness of the subfamilies of Orc. Only in few cases the problems are solvable in polynomial time pointing out the computational difficulty of evaluating QoS measures even in simplified models.Peer Reviewe

On the benefits of RINA over programmable optical networks for dynamic and smart resource management

In this paper, we describe the basics of the Recursive InterNetwork Architecture (RINA) and its advantages as a packet transport technology over programmable optical networks. In particular, its seamless integration over an SDN-controlled network infrastructure and its intrinsic capability of providing QoS is analysed and further discussedPeer Reviewe

On the benefits of RINA over programmable optical networks for dynamic and smart resource management

In this paper, we describe the basics of the Recursive InterNetwork Architecture (RINA) and its advantages as a packet transport technology over programmable optical networks. In particular, its seamless integration over an SDN-controlled network infrastructure and its intrinsic capability of providing QoS is analysed and further discussedPeer Reviewe

Benefits of programmable topological routing policies in RINA-enabled large-scale datacenters

With the proliferation of cloud computing and the expected requirements of future Internet of Things (IoT) and 5G network scenarios, more efficient and scalable Data Centers (DCs) will be required, offering very large pools of computational resources and storage capacity cost-effectively. Looking at todays' commercial DCs, they tend to rely on well-defined leaf-spine Data Center Network (DCN) topologies that not only offer low latency and high bisectional bandwidth, but also enhanced reliability against multiple failures. However, routing and forwarding solutions in such DCNs are typically based on IP, thus suffering from its limited routing scalability. In this work, we quantitatively evaluate the benefits that the Recursive InterNetwork Architecture (RINA) can bring into commercial DCNs. To this goal, we propose rule-based topological routing and forwarding policies tailored to the characteristics of publicly available Google's and Facebook's DCNs. These policies can be programmed in a RINA-enabled environment, enabling fast forwarding decisions in most scenarios with merely neighboring node information. Upon DCN failures, invalid forwarding rules are overwritten by exceptions. Numerical results show that the scalability of our proposal depends on the number of concurrent failures in the DCN rather than its size (e.g., number of nodes/links), dramatically reducing the total amount of routing and forwarding information to be stored at nodes. Furthermore, as routing information is only disseminated upon failures across the DCN, the associated communication cost of our proposals largely outperforms that of the traditional IP-based solutions.Peer ReviewedPostprint (published version

Scalable topological forwarding and routing policies in RINA-enabled programmable data centers

This is the peer reviewed version of the following article: Leon Gaixas S, Perelló J, Careglio D, Grasa E, López DR, Aranda PA. Scalable topological forwarding and routing policies in RINA-enabled programmable data centers. Trans Emerging Tel Tech. 2017;28:e3256, DOI 10.1002/ett.3256, which has been published in final form at DOI: 10.1002/ett.3256. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingGiven the current expansion of cloud computing, the expected advent of the Internet of Things, and the requirements of future fifth-generation network infrastructures, significantly larger pools of computational and storage resources will soon be required. This emphasizes the need for more scalable data centers that are capable of providing such an amount of resources in a cost-effective way. A quick look into today's commercial data centers shows that they tend to rely on variations of well-defined leaf-spine/Clos data center network (DCN) topologies, offering low latency, ultrahigh bisectional bandwidth, and enhanced reliability against concurrent failures. However, DCNs are typically restricted by the use of the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, thus suffering limited routing scalability. In this work, we study the benefits that replacing TCP/IP with the recursive internetwork architecture (RINA) can bring into commercial DCNs, focusing on forwarding and routing scalability. We quantitatively evaluate the benefits that RINA solutions can yield against those based on TCP/IP and highlight how, by deploying RINA, topological routing solutions can improve even more the efficiency of the network. To this goal, we propose a rule-and-exception forwarding policy tailored to the characteristics of several DCN variants, enabling fast forwarding decisions with merely neighbors' information. Upon failures, few exceptions are necessary, whose computation can also profit from the known topology. Extensive numerical results show that the proposed policy requirements depend mainly on the number of neighbors and concurrent failures in the DCN rather than its size, dramatically reducing the amount of forwarding and routing information stored at DCN nodes.Peer Reviewe