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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.
Judging by Appearance – It Happens in the Workplace This is one of the old sayings that really does come true, the clothes do make a person. What does it mean? For many people, it means that people judge by the clothes you wear. This is especially true in the workplace, but also for everyday life. Many companies nowadays have a dress policy in place to keep the appearances at work up. Reasons why companies have dress policies are of a great variety. Here is a review. One of the biggest reasons for companies to require nice appropriate clothing at least in their office area is visiting customers. If your employees need to be in contact with customers on daily or weekly bases or if customers do visit your offices in general, it is important that your employees make a good first impression. First impressions are very much guided by what you are wearing, your facial impressions and body posture. Therefore, if your customer see your employees working on their desks, it is important that the employees are dressed appropriately. For most workplaces this means a button down or polo shirt, dress pants or casual dress pants. In some instances, it is important for the employees to wear a tie and suit. For women, the codes are equivalent what the style of the clothing is referring to. Imagine what would happen if a customer comes into a company and the employee receiving the customer wears dirty, spotty, old and ripped clothes. In society that does not make a good impression, then the customer will most likely not want to do business with you. Another reason of why companies and employers would judge by your appearance is called professionalism. In the picture of professionalism at the workplace includes good appropriate clothing. It belongs to being a good employee as much as doing your job right and being polite and respectful to your boss and colleagues at your workplace. In society much is judged by the way you dress. If you have ever walked into one of the better department stores with a set of old, worn clothes, what kind of response do you get from the sales person? Often times they think you do not have enough money to buy here anyways and that is the way they treat you. They may not even give you the time of day, even if you have a lot of money. They judge you by what you have on and this is certainly the case in the workplace as well. If you want to project a good image, then take a good look at what you wear before you step out of your door in the morning. There are many places where a dress code is required or expected, such as the church, the opera, the theater, better restaurants and many other places. The workplace is just one of many and whether you like it or not, appropriate clothing is what can make or keep you get the job. Many Internet sites, books and people that offer advice on interviews and getting that job, will emphasize the importance of nice appropriate clothing and the impact it can have when you wear something that stands out from the crowd. Most people have been raised to think that proper dress attire is what you should wear at work, but for some it still is more a mystery to them than anything else. 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. |