Capacity Planning And Server Design For A Web Service

Abstract: Devo IT and its subsidiary SoftRobot AB are planning to offer a new service to its clients to further enhance growth of the company. This new service is a website that allows clients to upload documents that are converted into machine-editable text. The website and its underlying database are developed by SoftRobot's developer, but they lack the hardware. Using Cisco's PPDIOO network life cycle model, the three first stages of the project are identified. The "prepare" stage is already done by Devo IT where the project's justifications are discussed. In the subsequent "planning" stage, the needs of the project, are identified and a gap analysis is made of what is needed. The "design" phase elaborates which specific hardware and software is needed for the project. Three servers are needed, one for the main web server, a second for the database, and a third as a cache server for relieving the load on the database. These are planned as virtual machines, so that they can be located on the same physical machine and easily moved if necessary. The disk space required for the database is calculated with test documents since the average document size, the number of clients and how much they upload is known. Disks with adequate size can therefore be chosen. Different ways of improving performance and lowering failure rate of the disks are discussed with the means of RAID levels. These levels improve both disks reliability and performance in different ways.RAID 10 is designated for the database and RAID 1 for the web server and the caching server since those levels are the most suited for these applications. CPU and memory requirements are chosen based on availability and cost. Network bandwidth is analyzed and confirmed as sufficient with the help of the test database and since the bottleneck would be the CPU converting the uploaded documents. Software for backup and administration of the virtual machines are chosen comparing their functionality and the requirements for the project and their cost. After the hardware needs are identified, an cost analysis is made between hosting in Devo IT's server room or outsourcing it to an external company. It was revealed, as Devo IT suspected, that outsourcing costs more. The results of this thesis enables Devo IT to create a service with good quality, which will meet the clients expectations and also make Devo IT grow as a company with new clients and increased revenue.