For the purpose of multiple webs hosting customers the role of providing features of a dedicated server is done by Virtual Private Server (VPS), or also known as Virtual Dedicated Server (VDS). At first look it may possess a contradictory appeal; how one can have a dedicated server which is being served by multiple users? Isn’t it looking like a regular shared or virtual hosting environment? There is nothing to contradict in the statement that, with a Virtual Private Server the user has to share system resources for e.g. CPU and RAM with other users but the resources are owed and modified in such a manner that it is impossible to predict that the system possess someone besides the user on it, to a large extent ideally like a dedicated server. Thus resources are modified and arranged in such a way that each hosting client is allowed to exploit an allocated percent, means the resources assigned to a particular user will always be there all time ready to serve him/her.

Merits of Virtual Private Server (VPS) web hosting

Majority of users prefer complete command of their server environments and do not wish to share the server with several other users, who could easily exploit all the available resources and can cause problem to other users by creating unbalance. But at the same time several websites do not require a dedicated server. The Virtual Private Server (VPS) alternative is a very fabulous slot hosting solution for a fairly large lump of web hosting clients who prefer the stability of a dedicated server however on a smaller scale. With the resources setup in such a way that each person can only use what is in his/her own share, one’s site will be more steady because it will always have the same amount of access to the CPU, memory, as well as to the bandwidth. Virtual Private Servers are preferably more safe since even as the user share the memory and CPU time, he/she are allocated his/her own file system. For an instance, if a website on the server is hacked, the hackers will be able to admit to that particular file system only and can not harm the other existing websites. Besides all these advantages, A VPS is also affordable as compared to a dedicated server.

Demerits of Virtual Private Server (VPS) web hosting

As till now discussion was on the pros of a VPS and one might think that this is the finest thing .But there is another side of the coin as well as, not all providers setup or define Virtual Private Servers, also known as Virtual Dedicated Servers, the exact same way. One should ensure that provider guarantees the user that their setup is robust enough to knob the operations at a peak level. A commonly prevailing trick generally put into use by the providers in the field of reselling and shared space is ‘overselling’. It denotes selling more in terms of services than what is physically available, with the gamble that the end users wouldn’t exhaust up all the service that were advertised in front of them. In the dominion of VPS this can be a bit more severe, as at least the expectation is that one is working in a more vigorous environment and there are many clients running more intensive applications like message boards or custom web applications. A shortage of resources could result in causing problems for each one hosted on such a server, therefore evading the benefits of a VPS. In a mutual or dedicated environment the user might be able to access more quantity of resources during peak or spike periods but since the VPS environment restricts the user to use his/her own piece of server resources, it can come in front as a drawback.

With dynamic and changing technology web hosting is not sufficient, in the same manner there are some problems with VPS services also. The user has to tackle with the problems of CPU cycles and RAM distant for storing of space and bandwidth. So the user will see advertisements for hosting that might include MHz and MB RAM to go with the usual hosting related features. It is something difficult to calculate out how much CPU time or RAM the user might require, so one must look for a hosting provider that will provide him/her with some benchmarks and the ability to upgrade or downgrade the VPS service as and when required.

JUDGMENT:

- Permits complete control of user’s virtual server and its resources

- Permits the user to run web applications without unfavorably affecting other clients

- Flexible – cheaper than dedicated hosting, more expensive than shared

So Go ahead and best of luck!!!

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By this article one can get to know about the technology used in multiple server hosting as well as how to utilize it to maximize one’s site and security and uptime

Now the hosting of site has converted into a commodity where competition has raised to a very higher level and it’s very difficult to discriminate among the hosting plans on the basis of core plans, features and prices. Moreover choosing a host based on the cheapest price is not a better idea rather it thereafter proves to be very expensive in terms of reliability as well as possible loss of sales as a result of website downtime.

Choosing a best out of thousands of providers and resellers is a very scary task, which is rather based on hit and trial method. Even if hosting has become a commodity still while choosing for new host one should look for reliability.

Now at the heart of any hosting company’s reliability is redundancy. Redundancy offers an alternative remedy in case any problem occurs. This is to ensure continuity of work as seamlessly and transparently as possible.

There are several hosts, which employ redundant network connections. These are the high-speed pipes that route data from the server to one’s web browser. As against this, redundant ‘multiple web servers’ are quite rare and expensive and so are rarely used. They are expensive due to use of costly routing equipment, which has previously been used, only in mission critical applications of Fortune 500 companies.

There is yet another very neat but little known Domain Name Server (DNS) feature called ’round robin’ which allows the selection and provision of a particular IP address from a ‘pool’ of addresses when a DNS request arrives.

The Domain Name Server (DNS) database maps a host name to their IP address. Thus instead of remembering a vast series of numbers (IP address) one can just type in his/her web browser www.mydomain.com, to get to one’s website.

Now in order to publicize DNS info throughout the market it will typically take minimum 2 to 3 days. That is the reason when one registers or transfer a domain name it isn’t immediately available to the person browsing the web.

This delay has foiled the security benefits of hosting one’s site on multiple servers, as the site would be down for a couple of days in case of any problem with one server. As a remedy one has to change his/her DNS to reflect the second server and has to wait for several days before the change was picked up in routers on the Internet.

There is yet another solution for the above problem i.e. the round robin DNS strategy that solves this quandary, by mapping one’s domain name to more than one IP address.

One should now select that hosting companies which employs the DNS round robin technique in conjunction with’failover monitoring’.

The DNS round robin fail over monitoring process starts by a web hosting company setting up one’s site on two or more independent web servers. Thus one’s domain name will therefore have 2 or more IP Addresses assigned to it.

Thereafter the fail over monitor watches one’s web server(s) by dispatching data to a URL one specifies and looks for particular text in the results. Now when an error is returned from one of an IP address, it pulls that IP address out of the list. The DNS thereafter points one’s domain name to the working IP address/s

In case any of the user’s IP’s come back online they are restored to the IP pool. This helps in effectively and safely keeping one’s site online even if one of the web servers is down.

In this case an average failure detection and recovery time with a system is very low with just 15 minutes. However this time varies depending on site’s speed as well as the nature of the failure and also how long other ISP’s cache (save) one’s DNS information.

The time taken for other ISP’s caching one’s information can be manipulated in the fail over monitor by lowering the “time to live” (TTL) cache settings. These are the settings used by other ISP’s in order to determine how long to cache one’s DNS information.

One must also keep in mind the matter of how frequently data is synchronized between his/her website’s servers. Now this comes under the hosting company’s responsibility, and this becomes complicated where databases and user sessions are involved.

The most elegant solution to multi server hosting is very expensive hardware based fail over monitoring systems that point a virtual IP address to other ISP’s, while behind the scenes juggling a number of unique IP addresses on different servers.

This way, the whole issue of ISP’s caching one’s information does not come into play.

Thus in order to get 99.99995% uptime, without spending big amount of money, the technology is readily available and certain proprietary failure monitoring systems are now relatively cheap to apply.

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