Database Servers & Pricing
What is Database Server ?
A database server is a computer program that provides database services to other computer programs or computers, as defined by the client–server model. The term may also refer to a computer dedicated to running such a program. Database management systems frequently provide database server functionality on the client–server model for database access.
A database server allows you to take measures to increase the security of your data and all the data of your organization is stored in one location.
The WroxCommerce components will need to constantly query the database to enable the ASP layer to present the site to the user, so this is obviously a critical part of the solution.
We could get away with a single high-end database server, but if this dies for any reason, the entire Web site will have a catastrophic problem. In this situation, we say there would be a “single point of failure” and. short of the ISP simply vanishing off of the planet, there should never be one of these single points of failure in your solution. To eliminate the single failure point for these database requests, create two identical machines to be the database server and connect them together using the Microsoft Cluster Service, again included with Windows NT 4 Enterprise Edition.
An important thing to note here is that previously we were balancing Web requests across a collection of servers; now we’re talking about balancing database requests from the cluster of Web servers across two, additional, database servers. Microsoft Cluster Service only supports two machines, and these machines have to be identical. This is in marked contrast to the Load Balancing Service that can support up to 32 machines of varying configurations.
Once we have all of the servers, we have to provide connectivity between the parts. In these situations, a private network is usually constructed to connect all of the parts of the server farm together. Sectioning off the traffic to manage the network is done to prevent other network traffic from bogging down communication between the servers in the farm. Private communication is typically done over a 100Mb/s network, but as the price of gigabit Ethernet continues to fall, we’ll see more server farms enjoying gigabit connectivity for private communication.
Finding pricing information for hosts providing the basic dedicated rack in a server solution is relatively straightforward, although as we discussed before, you’ll have to investigate each ISP carefully to determine their ability to provide the service you need. Basically, you pay for what you get, so the more money you spend, the closer to a backbone (see following discussion) your provider will be and the more money they spend on systems administration and support.
The rest of this chapter details a lot of points you should look out for. Remember to factor in the cost of software licenses for companies that do not provide you with software, as this can be a considerable cost in its own right.
Pricing for clustered solutions is a little harder to come by, because no two solutions are the same (apart from local clustering, some companies offer geographically dispersed solutions). A good way to find other ISPs is to trace the connection to major Web properties, such as eBay, Yahoo and CNet and see which service providers they use.
If you have a client-server architecture where the clients need process data too frequently, it is better to work with a database server.