High Availability Procedures and Implementing a Pooler

Nowadays production flows are modular, each module in the enterprise being specialized and used to achieve a particular task. In many cases the modules are interconnected and materials are sequentially processed in each module resulting a final, unique product or assembly. One typical such production module is a flexible cell/system using multiple robots. In such complex enterprise environments, providing continuous services for applications is a key component of a successful implementing of robotized manufacturing. High availability (HA) is one of the components contributing to continuous service provision for applications, by masking or eliminating both planned and unplanned downtime of systems and applications. This is achieved by eliminating hardware and software single points of failure (SPOF). The systems configured for high availability are a combination of hardware and software components configured to work together to ensure automated recovery in case of failure with a minimal acceptable downtime. A high availability solution will ensure that the failure of any component of the solution either hardware, software or system management, will not cause the application and its data to become permanently unavailable. High availability solutions should eliminate single points of failure through appropriate design, planning, hardware selection, software configuring, application control, carefully environment control and change management discipline. In short, one can define high availability as the process of ensuring an application is available for use by duplicating and/or sharing hardware resources managed by a specialized software component. A high availability solution in robotized manufacturing provides automated failure detection, diagnosis, application recovery, and node (robot controller) re integration. The chapter discusses the implementing of a high availability solution in a robotized manufacturing structure (cell, line). The solution is based on a High Availability Linux Cluster which is responsible for data availability and preservation on a NFS (Network File System) file system, and a second cluster – Fabrication Cluster (FC) which runs on Adept robot controllers, developed under the V+ programming language.

In recent decades, virtualization as an abstraction from physical hardware has become a popular solution to resource isolation and server consolidation. With the surge in adoption of virtualization technologies, ensuring High Availability (HA) for applications hosted in virtualized environments emerges as an important problem and has garnered substantial attention. In this paper, we present a brief comparison of virtualization technologies from a HA perspective. The state-of-the-art HA solutions in two mainstream types of virtualized platforms (i.e., hypervisor-based platform and container-based platform) are respectively investigated in terms of limitations and features such as live migration, failure detection, and checkpoint/ restore. One of our key findings is that, compared with hypervisor-based platforms, HA features in container-based platforms are far from enough. From a HA perspective, extensions on top of container technologies are required.

A large class of modern distributed file systems treat metadata services as an independent system component, separately from data servers. The availability of the metadata service is key to the availability of the overall system. Given the high rates of failures observed in large-scale data centers, distributed file systems usually incorporate high-availability (HA) features. A typical approach in the development of distributed file systems is to design and develop metadata services from the ground up, at significant cost in terms of complexity and time, often leading to functional shortcomings. Our motivation in this paper was to improve on this state of things by defining a general-purpose architecture for HA metadata services (which we call RMS) that can be easily incorporated and reused in new or existing file systems, reducing development time. Taking two prominent distributed file systems as case studies, PVFS and HDFS, we developed RMS variants that improve on functional shortcomings of the original HA solutions, while being easy to build and test. Our extensive evaluation of the RMS variant of HDFS shows that it does not incur an overall performance or availability penalty compared to the original implementation.

인터넷 환경의 급속한 발전과 더불어 국내외 미션 크리티컬한 비즈니스 환경이 온라인에 의해 서비스 되고 있다. 따라서 웹 환경을 통해 처리되어야 할 정보의 양의 급증과, 이의 처리를 위해 여러 개의 단일 서버를 고속의 네트워크로 연결한 고가용성 구현이 가능한 클러스터 컴퓨팅 시스템이 등장하게 되었다. 그 결과 클러스터 기반 DBMS에 관한 연구와 상용화된 솔루션을 통해 국내외적으로 활발히 진행 중이며, 이에 따라 클러스터 기반 DBMS를 효율적이고 최적화된 상태의 관리 연구는 미흡한 실정이다. 따라서 본 논문에서는 클러스터 기반 DBMS를 위한 고가용성 클러스터 솔루션의 최적화된 관리 기법과 이론에 대해 알아본다. In these days, Internet environment are very quickly development as well On-line service have been using a online for the mission critical business around the world. As the amount of information to be processed by computers has recently been increased there has been cluster computing systems developed by connecting workstations server using high speed networks for high availability. As a result, this study on a cluster based DBMS and common solution of DBMS venders has been studying with a wide range, as well as It is not good study a management skill for the cluster-based DBMS efficiently and optimization. accordingly, This study find out optimization managements skill and theory of he High availability solution on cluster-based DBMS.

Broadband Power Line Communications (BPL) is a technology that has proved to be a very suitable option for the deployment of Smart Grid solutions. It provides a low cost, proprietary, high performance future-proof backhaul between Secondary Substations. This paper will focus on the description of the different "Fault Cases" that might occur in medium voltage BPL communication architecture and their consequent High Availability solution, taking advantage of Iberdrola's experience in the use and maintenance of this technology along its large scale Smart Grid deployment. The description of the High Availability functionality and the results of the tests developed so far are presented in this paper so that utilities might find it useful to provide an added value in their own Smart Grid deployments.

In our increasingly wired world, there is a stringent need for the IT community to provide uninterrupted services of networks, servers and databases. Considerable efforts, both by the industrial and academic community have been directed to this end. In this paper, we examine the requirements for high availability, measures used to express it, and approaches used to implement this for databases. We present a high availability solution, using off the shelf hardware and software components, for transactions based applications and give our experience with this system.

Cloud computing provides virtual resources so that end-users or organizations can buy computing power as a public utility. Cloud service providers however must strive to ensure good QoS by offering highly available services with dynamically scalable resources. HA-OSCAR is an open source High Availability (HA) solution for HPC/cloud that offers component redundancy, failure detection, and automatic fail-over. In this paper, we describe HA-OSCAR as a cloud platform and analyze system availability of two potential cloud computing systems, OSCAR-V cluster and HA-OSCAR-V. We also explore our case study to improve Nimbus, a popular cloud IaaS toolkit. The results show that the system that deploys HA-OSCAR has a significantly higher degree of availability.

It is important for any organization to handle increase in data; normally this is the job of the DBA in organization to take care of this data growth, along with its protection and its availability. High availability of data is also most important for organizations, for that purpose, shared storage is usually the solution, for example, SAN or NAS storage as Microsoft Cluster Database instances. Mostly Organization does not have shared storage in their infrastructure, which was required for Microsoft cluster SQL database instance; due to that they used other native methods to implement like log shipping or database mirroring, which was not efficient method for high-availability and disaster-recovery solution. After that, Microsoft introduced native method called SQL AlwaysOn method that could be implemented without using SAN and NAS storage method to implement high availability and disaster recovery without using shared storage. SQL AlwaysOn option is using only Microsoft cluster service and shared folder between the nodes. This paper written for DBA and System Administrators; and is implementation of Microsoft SQL Database tier step by step.

The development of open-source FPGA CAD tools is challenging. Vendor CAD tools exist but are closed-source and specific to each FPGA family. These tools give limited opportunity for customizing and also have the disadvantage of long compile times. Several open source tools have been built, but the quality of results from these tools is still far behind commercial tools. This research is aimed at bridging some of the gap between commercial and open-source FPGA CAD tools by tuning policies of existing implementation algorithms. We build a set of synthetic benchmarks to identify the mapping between input circuit patterns and policies of a given CAD algorithm and architecture. This work discusses the framework for policy tuning and is aimed at showing that algorithm policies need to adapt to the input circuit. We demonstrate our framework with the packing step of the FPGA CAD flow and show how our approach can be used to improve the quality of results in open-source tools.

With forensics playing such a crucial role in today's data-driven world, this paper addresses the need to explore the different mobile device forensic tools available. Open Source and Commercial tools are two domains in close contention, with contrasting considerations such as accessibility and security. This paper aims at performing a comparative analysis of the various commercial and open source mobile device forensic tools, with respect to predefined software parameters and by employing a cross-device and test-driven approach. The test scenarios are structured to assess whether the selected tools possess the capabilities of a holistic one, while responding to threats and scenarios pertaining to the digital realm. The Commercial Tools under consideration are MOBILedit! Forensic (including Phone Forensics Express) and Cellebrite's UFED Physical Analyzer, while the Open Source Tools are — The Sleuth Kit (including Autopsy) and SANS SIFT. The result of this paper is a comparison matrix, which could help in identifying the best-fit solution as per the need of the investigation. It could also indicate the degree to which open source tools are comparable to (or better than) their commercial counterparts, and answer questions like — Can open source tools be a suitable replacement for the proprietary tools? Can this in reality, be a feasible shift for the forensic industry?

As businesses increasingly rely on IT for their mission-critical operations, continuous availability is a universal concern. Nowadays, virtualized platform has become the popular option to deploy complex enough services. Deployed services are expected to be always, available, but these long running services are especially sensitive to suffer from software aging phenomenon. Software aging of virtual machine monitors (VMMs) is becoming critical because performance degradation or crash failure of a VMM affects all virtual machines (VMs) on it. To counteract this issue, we deploy software rejuvenation methodology. To eliminate the service outage during software rejuvenation process, we combine the rejuvenation with live migration technology. Live VM migration enables a running VM on a host serer to move onto the other host server with very small interruption of the execution. Live VM migration depends on VMs placement and efficient resource available is required. The idea behind our paper is two-fold. First, we present the optimization of the resource usage as accepting as many services as in virtualized environment which support of VM live migration. Second, to demonstrate how much it can improve system availability, the stochastic Petri nets model a virtualized server system in case of using time based software rejuvenation for VMM is presented. Finally, we perform the numerical analysis to evaluate the model.

We present a collaborative, self-configuring high availability (HA) approach for stream processing that enables low-latency failure recovery while incurring small run-time overhead. Our approach relies on a novel fine-grained checkpointing model that allows query fragments at each server to be backed up at multiple other servers and recovered collectively (in parallel) when there is a failure. In this paper, we first address the problem of determining the appropriate query fragments at each server. We then discuss, for each fragment, which server to use as its backup as well as the proper checkpoint schedule. We also introduce and analyze operator-specific delta-checkpointing techniques to reduce the overall HA cost. Finally, we quantify the benefits of our approach using results from our prototype implementation and a detailed simulator.

Digital Systems plays an important role in today’s modern technology. The practical implementation of digital circuits in laboratories leads to a complex wired circuits and testing finds difficult. The damage of ICs, breadboards due to complexity needs replacement. This paper disseminates the virtual use of all the components using an open source tool. Digital circuits are of combinational logic circuits and sequential circuits. Implementation of combinational circuits using logic gates in virtual mode is described. Autodesk Tinkercad is an open-source software tool for the development of system. The design of combinational circuits such as Adder, Subtractor, Encoder, Decoder, Code converters are implemented with ICs using Tinkercad tool.

This chapter describes a pragmatic approach to using open source and free software tools as valuable resources to affect learning of software industry practices using iterative and incremental development methods. The authors discuss how the above resources are used in teaching undergraduate Software Engineering (SE) courses. More specifically, they illustrate iterative and incremental development, documenting software requirements, version control and source code management, coding standards compliance, design visualization, software testing, software metrics, release deliverables, software engineering ethics, and professional practices. The authors also present how they positioned the activities of this course to qualify it for writing intensive designation. End of semester course evaluations and anecdotal evidence indicate that the proposed approach is effective in educating students in software industry practices.

The phenomenon of high availability (HA) is of vital importance in cloud architecture. This paper proposes an HA verification framework, called HAVerifier, for OpenStack, a popular open source cloud platform. Fault injection technology has been adopted to verify the system's reliability by determining its health status after injecting faults. The framework proposed in this paper verifies the availability of services by injecting faults into the different components of OpenStack. Service indicators (for example, downtime) are monitored after the faults are injected. The collected metrics are compared with the provided service level agreement to verify whether the platform's availability meets the requirements. The fault injection steps can be implemented dynamically using the proposed framework, and the faults injected into the platform can be restored without manual intervention. Finally, a prototype for this framework is implemented to prove its applicability to verifying the HA of the OpenStack platform.