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Web Hosting - Redundancy and Failover
Among the more useful innovations in computing, actually invented decades ago, are the twin ideas of redundancy and failover. These fancy words name very common sense concepts. When one computer (or part) fails, switch to another. Doing that seamlessly and quickly versus slowly with disruption defines one difference between good hosting and bad.
Network redundancy is the most widely used example. The Internet is just that, an inter-connected set of networks. Between and within networks are paths that make possible page requests, file transfers and data movement from one spot (called a 'node') to the next. If you have two or more paths between a user's computer and the server, one becoming unavailable is not much of a problem. Closing one street is not so bad, if you can drive down another just as easily.
Of course, there's the catch: 'just as easily'. When one path fails, the total load (the amount of data requested and by how many within what time frame) doesn't change. Now the same number of 'cars' are using fewer 'roads'. That can lead to traffic jams.
A very different, but related, phenomenon occurs when there suddenly become more 'cars', as happens in a massively widespread virus attack, for example. Then, a large number of useless and destructive programs are running around flooding the network. Making the situation worse, at a certain point, parts of the networks may shut down to prevent further spread, producing more 'cars' on now-fewer 'roads'.
A related form of redundancy and failover can be carried out with servers, which are in essence the 'end-nodes' of a network path.
Servers can fail because of a hard drive failure, motherboard overheating, memory malfunction, operating system bug, web server software overload or any of a hundred other causes. Whatever the cause, when two or more servers are configured so that another can take up the slack from one that's failed, that is redundancy.
That is more difficult to achieve than network redundancy, but it is still very common. Not as common as it should be, since many times a failed server is just re-booted or replaced or repaired with another piece of hardware. But, more sophisticated web hosting companies will have such redundancy in place.
And that's one lesson for anyone considering which web hosting company may offer superior service over another (similarly priced) company. Look at which company can offer competent assistance when things fail, as they always do sooner or later.
One company may have a habit of simply re-booting. Others may have redundant disk arrays. Hardware containing multiple disk drives to which the server has access allows for one or more drives to fail without bringing the system down. The failed drive is replaced and no one but the administrator is even aware there was a problem.
Still other companies may have still more sophisticated systems in place. Failover servers that take up the load of a crashed computer, without the end-user seeing anything are possible. In fact, in better installations, they're the norm. When they're in place, the user has at most only to refresh his or her browser and, bingo, everything is fine.
The more a web site owner knows about redundancy and failover, the better he or she can understand why things go wrong, and what options are available when they do. That knowledge can lead to better choices for a better web site experience.
Web Hosting - Bandwidth and Server Load, What's That? Two key performance metrics will impact every web site owner sooner or later: bandwidth and server load. Bandwidth is the amount of network capacity available, and the term actually covers two different aspects. 'Bandwidth' can mean the measure of network capacity for web traffic back and forth at a given time. Or, it sometimes is used to mean the amount that is allowed for some interval, such as one month. Both are important. As files are transferred, emails sent and received, and web pages accessed, network bandwidth is being used. If you want to send water through a pipe, you have to have a pipe. Those pipes can vary in size and the amount of water going through them at any time can also vary. Total monthly bandwidth is a cap that hosting companies place on sites in order to share fairly a limited resource. Companies monitor sites in order to keep one site from accidentally or deliberately consuming all the network capacity. Similar considerations apply to instantaneous bandwidth, though companies usually have such large network 'pipes' that it's much less common for heavy use by one user to be a problem. Server load is a more generic concept. It often refers, in more technical discussions, solely to CPU utilization. The CPU (central processing unit) is the component in a computer that processes instructions from programs, ordering memory to be used a certain way, moving files from one place to the next and more. Every function you perform consumes some CPU and its role is so central (hence the name) that it has come to be used as a synonym for the computer itself. People point to their case and say 'That is the CPU'. But, the computer actually has memory, disk drive(s) and several other features required in order to do its job. Server load refers, in more general circumstances, to the amount of use of each of those other components in total. Disk drives can be busy fetching files which they do in pieces, which are then assembled in memory and presented on the monitor, all controlled by instructions managed by the CPU. Memory capacity is limited. It's often the case that not all programs can use as much as they need at the same time. Special operating system routines control who gets how much, when and for how long, sharing the total 'pool' among competing processes. So, how 'loaded' the server is at any given time or over time is a matter of how heavily used any one, or all, of these components are. Why should you care? Because every web site owner will want to understand why a server becomes slow or unresponsive, and be able to optimize their use of it. When you share a server with other sites, which is extremely common, the traffic other sites receive creates load on the server that can affect your site. There's a limited amount you can do to influence that situation. But if you're aware of it, you can request the company move you to a less heavily loaded server. Or, if the other site (which you generally have no visibility to) is misbehaving, it's possible to get them moved or banned. But when you have a dedicated server, you have much more control over load issues. You can optimize your own site's HTML pages and programs, tune a database and carry out other activities that maximize throughput. Your users will see that as quicker page accesses and a more enjoyable user experience. The Options For Online Creative Writing Courses (online creative writing courses) Online courses are ever growing in popularity. Many consumers don’t have the patience, money, or time to attend regular college classes, so many of them has turned to the Internet as their means of education. The online course phenomenon is especially helpful for many writers, as more and more writers find it both convenient and helpful to take online creative writing courses. Online courses are also known as distance learning courses, because of course the student is not in the classroom, or even the school when the course is taken. These distance courses have been seen as one of the best ways for a busy writer to brush up on their skills or learn new ones. Taking creative writing courses gives writers many options, such as working at their own pace. Many writers are too busy to attend class and enjoy the freedom giving by online courses. The distance courses give students the freedom to work at their own pace while learning everything that is needed. Students also don’t have a set time for the courses, so they may choose when they want to learn. An online course gives the writer time to fulfil all of their other duties. Online creative writing courses are easy to find, and there are plenty of programs offered by online writing schools. Writers Weekly University is one online school that offers creative writing courses for the busy writer. The university offers e-mail courses for freelance writers and aspiring novelists. They offer courses such as The Art of the Press Release, Finish Your Novel in eight Weeks, and How to Write a Cookbook and Sell It. Published writers and editors usually teach the online courses offered by Writers Weekly University. The courses may be inexpensive, and typically range from $25 to $745, but the price is based on the length and complexity of the course. Writers’ Village University is also a school that offers online creative writing courses. Writers’ Village University is one of the most popular sources for online writing courses, and offers more than 250 courses. The courses offered by this university are paid for in a non-traditional way. There is no payment required for the actual courses taken, but instead a membership fee, which gives writers unlimited access to hundreds of online creative writing courses. The Writers’ Village University is also one of the most inexpensive with a membership fee of $69 per year or $10.99 per month, which for many is less than the cost for Internet access. The university offers courses in fiction writing, comedy writing, literature, business writing, and poetry. However, the schools for writers don’t stop with the Writers’ Village. There are many more online schools that offer writing courses to consumers. Writers Online Workshops is also an online writing university that offers writers the creative courses they want and need. This university is facilitated by Writer’s Digest, and the courses are said to be taught by the best writers. The creative writing courses at this university range from fiction writing to business writing to poetry to composition. The Writers Online Workshops are far more expensive than other online creative writing courses, and typically start at $200. The courses provided by this university also require textbooks, so students will feel as if they are attending a regular university. Online creative writing courses may not be for every writer, but they can help a writer improve their skills while obtaining some education in the field they love. The courses may not be foolproof, but they may be a great benefit to every writer who wants to take them and wants to learn more about writing. |