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Email Blacklists
Posted on June 17th, 2010 by Victoria Pal in TechSooner or later email blacklists become the nightmare of most system administrators. Long story short - when your email provider is reported as a source of email spam, a lot of your email messages won't reach your family, friends, business partners, loyal and prospective customers alike.
Becoming part of a blacklist isn't what gets other email providers to filter you, it is the way they decide to do so. Blacklisting causes problems when the administrator decides to simply filter out all emails coming from a network device on a blacklist. Medieval doctors did a similar job when taking off an arm to save the patient from an infected finger. Clean email has no chance of reaching its intended location. Decent e-mail service providers usually filter spam, employing methods that utilize multiple filters before deciding whether an email message is spam or not.
Content Delivery Networks
Posted on June 16th, 2010 by Victoria Pal in TechAlmost all of us enjoy the benefit of a Content Delivery Network, whether we realize it or not. Content Delivery Networks (CDN) also referred as Content Distribution Networks is what you call a system of network hardware containing copies of data located in various geographical locations, depending on the local demand from clients requesting the resources.
Content delivery networks are especially useful for delivering rich media content to users from different geographical locations, avoiding delay and bandwidth overload near the main server. CDNs can contain all types of data, but most often they are used to distribute data which demands high bandwidth. A few rough examples are downloadable software, media files and documentations, multimedia streams, online games as well as database queries, etc.
DDoS Attack
Posted on June 15th, 2010 by Victoria Pal in TechThe end goal of the Denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is to make a resource unavailable to its users. The attack can be carried out on different levels, depending on the target and the people involved. In essence, the attack represents a highly intense attempt by one person or more to hinder websites or specialized internet services from running properly, causing financial losses to that resource's owner.
Depending on the motivation behind the attack, different targets might suffer from it. The attack can be implemented by a single person, carrying out a personal agenda. Such an attack is improbable to cause too much trouble and will only be temporary. A much bigger problem is organized attacks performed by a group of individuals in pursuit of financial gains. Such attacks can be sustained for longer periods of time and might as well ruin companies relying on online presence. Banks, online retailers, government sites, payment gateways, and even root nameservers can become easy prey for organized DDoS attacks.
Server Cache
Posted on June 10th, 2010 by Victoria Pal in MonitoringWeb caching describes the process of storing frequently used objects closer to the user through browser, proxy or server cache. Caching frequently used content has a positive effect in most cases because it reduces server load, bandwidth and latency. It also helps increase the responsiveness for users on the web.
Modern browsers support caching and require most elements of a page only during the first time a user opens that page. Then CSS files, images and other media are stored in a dedicated folder. This leads to faster loading times and better user experience. The whole process happens without any input from the user.
Server Virtualization Is Growing
Posted on June 2nd, 2010 by Victoria Pal in Tech"I think there is a world market for maybe five computers" is a famous misquote of Thomas J. Watson. The same Tom Watson, who took Computing Tabulating Recording Corporation and turned into what is today known as IBM. In essence, whoever said that the world will only need 5 computers wasn't totally wrong. Virtualization was first implemented in 1960 to aid better utilization of large mainframe hardware. 50 years later, it has grown to be part of all Fortune 100 success stories.
Lately, "fake servers" became a slightly satiric way to say "virtual servers". Why? Mainly because they are gaining a larger market share. Large enterprises were quick to adopt the virtual machines approach, while small business started late. However, by year-end 2010, enterprises with 100 to 999 employees will have a higher penetration of virtual machines deployed than the Global 500. For long years, small businesses could not afford even the entry level products, and this is what changed lately. Increased competition by server vendors has made server virtualization technology affordable to smaller companies.