Web server cluster
Written by wwwhostingdirectory.com
Even when you use a dedicated server, the traffic and the load can be too much. This happens when the website becomes hugely popular and has traffic that goes into millions of clicks every day. A good example of this is a website like Wikipedia. Wikipedia has such a huge database and so many hits and requests every minute of the day that one server even with multiple processors would be ridiculously below requirement. The solution is to use a web server cluster.
A web server cluster is a collection of servers that work together to accomplish what one server cannot possibly do. The simplest form of server cluster is similar to the mirror database and its function. There are two servers, one acts as the main server, and the other is the back-up server. If for some reason the main server fails, the back-up server takes over and functions, making sure that your website suffers no downtime. Request dispatching mechanism is at the heart of any server clustering techniques. First, an address is typed by the client. Then, the Domain Name Client, or the DNS, translates this name to an IP address. Once this is done, the request is taken either to a router or straight to be server machine. If it reaches a router, the IP address gets mapped to yet another and final IP. Either way, the request gets to its final destination, and the HTTP redirection mechanism lets the server reject it and get it sent to another host.
Managing web server clusters can be difficult. There are certain platforms and applications that will let you manage the cluster of servers as one server, but these applications are not foolproof. Some of them might make the management relatively smoother, but you can’t realistically expect to work on a web server cluster the same way you work on a single server.
Cluster server program’s try to manage the servers as a single system. They detect the failure of any server in the cluster. Having a web server cluster can also help you recover from the failure or overload on any one server. The most important function of a web server cluster is load balancing. With the right cluster server program, requests will be routed to free servers in the cluster. This avoids overloading. Even if one server does overload and crash, the rest of the servers in the cluster can balance the requests between them and make sure that the cluster works smoothly without causing your website any down time.
The best way for a web server cluster to work is in combination with a network load balancer. This way, the chances of overloading are drastically reduced. This is one of the most reliable combinations and ensures that the reliability of your website does not suffer. This will keep your load balanced while keeping the response time as low as possible.
Web server clustering technologies are transparent, that is, guests and customers visiting the site will not have any inkling of them.
Even when you have a web server cluster, you might begin to face the problems you were facing when you had only one server supporting your website. You can decide whether it’s a boon or a bane – this means that you will have to upgrade your web server cluster, and make sure that you have enough servers in your cluster, which will be expensive. But the good news is that if this happens, you ought to be able to easily afford it, because this can only mean that your website is getting the kind of traffic all online business owners dream of. |
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