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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.

Save the Earth and Get Free Stuff from Recycling with Freecycle Get ready to become more earth-conscious by freecycling. What is freecyling and how can it help the environment? As the name implies, the concept of freecycling is directly inspired by the idea of recycling. Freecycling is not only a great way to help protect the earth's natural resources and prevent the flooding of landfills, it is also a great and viable way to find goods and services that you really need. Thus, freecycling is a very practical approach to many of the problems that we face today. What is the Freecycle Network? Freecyling has found a home at freecylce.org. The Freecycle website is home to the Freecycle network. This network is made up of over 4,000 groups with a total member population of over four million people worldwide. The freecycle philosophy is spreading like wildfire as more and more people come to learn more about this exciting and environmentally friendly new exchange network. The Freecycle Network represents an entirely grassroots, nonprofit effort that allows people to get and give their stuff fro free in their own cities and towns. Freecycle allows all the good stuff that would normally end up in a landfill in the hands of someone who can really use it. A local volunteer who is in charge of coordinating the freecycling efforts and awareness in their own community moderates almost each local freecycle group. Membership to join the Freecycle Network is absolutely free and open to anyone with something to give, or get. In order to join the Freecycle Network today, simply find your local community by searching in the search box. The Ins and Outs of Freecycling for the Freecyling Newbie No freecycling is not a new, cutting edge sport—it is an easy way to manage one's owns possessions so that you leave a smaller footprint on the Earth. If you are new to freecycling, perhaps you could use a little guidance on how to get into the freecycling side of things. Here are some things you need to know before you get started in the exciting world of freecycling. Take the Right Kinds of Precautions When Freecycling One of the most important things you should do is to always make sure to freecycle safely. Freecycling often means coming into direct contact with seemingly perfect strangers. You should always maintain your safety and privacy when interacting with other members of your freecycling group. If you do not know someone well, avoid giving out your personal contact information right away. Whenever possible, try to make exchanges in a public setting or at least make sure that you are not alone with picking up or waiting for someone to pick up the item that is being freecycled. Tips and Hints for Using the Freecylce List What happens once you has signed up to become a part of your local freecycling group? Once you have successfully joined, you can use your local freecycling list to communicate with other members. You can post a message, read messages and send email to your local groups collective address. Most local freecycling groups use local yahoo groups to communicate. To send an email to the list, simply send an email to your local groups email address. If for some reason you wish to unsubscribe to your local freecyling group, you simply need to send an email to the unsubscribe address that is listed at the bottom of each email from your local freecycling group. For information on posting, replying or reading messages to your local yahoo group, visit your local group and become familiar with the delivery options. If you have any questions, contact your group's moderator directly.

Web Hosting - Domain Name Changes and How They Affect You New domain names are registered all the time, and ones previously registered expired. Sometimes that's the result of simple neglect. The owner of the name chose not to renew his or her ownership, so the name became available for someone else to use. In rare cases, a highly original mind managed to think of a new one. In the other common scenarios, someone chose to just let it go or sell it. When you choose to change your domain name, there are actually two separate steps involved: releasing the old name, and adopting the new one. But, just as the postal system can have difficulty forwarding your letters when you change your personal name, changing your domain name brings certain difficulties. One of the most prominent is the fact that any name change requires a change to thousands of DNS Servers around the globe. DNS (Domain Name System) is the set of software/hardware components that allows domain names to map to IP addresses. IP addresses are what are actually used 'under the covers' when one computer communicates with another. Note that there isn't always a 1:1 correspondence between a name and an IP address. One IP address can serve multiple domain names and one domain name can have multiple IP addresses. For the sake of simplicity, we'll stick to the common case here. DNS servers around the world maintain internal databases that match the name to an IP address. Not all servers have all pairs of names/addresses. A series of complex routines allows a request to be forwarded when the particular DNS server doesn't have a needed record. When you acquire a domain name that used to be associated with a given IP address, the odds of you acquiring the same IP address are extremely low. In the unlikely case, for example, that you acquired the domain name yahoo.com, you would almost certainly not get the IP address that was matched with it (unless you bought the Yahoo! company). So, as a result of the change, the name/IP address pair is no longer what it was. A similar circumstance exists when you retain your IP address, but want to change the domain name associated with it. In either case, the pairing has changed. The catch is this: when the change takes place, those DNS databases are not all updated instantaneously around the world. Even apart from the limited speed with which computers and networks operate, (and neglecting the human factor if/when the change is made manually to more than one server) the reason is something called caching. In order to communicate efficiently, DNS servers are designed to assume that changes will be relatively rare. Just as with the postal system, you don't move your address or change your name every minute. Since that's true, in general, the name/IP address pair is cached. A cache is a set of stored information that is reused so that fresh information doesn't have to be communicated with every request for a web page or data. A chain of DNS servers pass requests to the last known address. There is usually more than one system between your computer and the server you want to communicate with. Most of the time, that's your current name/address. When you change the name, that pair is no longer valid. In order to propagate the new name/address pair (so the terminology goes), that cache has to be refreshed. Something similar happens when you establish an entirely new name. That name is first associated with an IP address and that pair has to be communicated to DNS servers around the world in order for you to be able to reach any one of them at random. But DNS servers don't do that until they are requested to do so by your action of asking for information from a remote server. Because of that, but chiefly because of caching, it can take quite a while for the new pair to become known around the Internet. Caches can expire and get refreshed in a few minutes or a few hours. It varies. That time can be as short as an hour or less, if the path between your computer and the web server is very simple and only one DNS server needs to be updated. Or, it can take up to 48 hours or more. Though the 'official' range is often given by registrars as 24-48 hours, the average is closer to about six hours. But that's an average. The actual time in any given case can (and does) vary widely. In the meantime, a number of effects can occur. The most obvious is that, since the name/IP address pair can't be resolved properly, you don't reach the server you want. Your browser points to the old one (in the rare case it's still accessible by that name and address), or it simply reports there's no such name at that address. So, when registering a new name or buying an old one, you should establish the site, but not advertise it for at least a couple of days. Better to wait to get visitors than to turn them off by being 'not at home' when they call.