• Category Archives Technology
  • A DNS Failover Service – Is it right for you?

    Posted on by Mikel

    Over the years, DNS Failover has become a very popular service primarily due to the fact that it is relatively inexpensive and fairly easy to deploy and manage. But is it the right solution for your organization? In this article, we’ll outline what DNS failover is and provide an overview of the benefits and appropriate uses for this type of technology.

    What is DNS Failover?

    First, we must define what DNS failover is before trying to understand whether or not it offers benefits. Simply put, DNS failover is an add-on feature of a DNS Service and is a system that consists of two main components. The first component monitors servers or devices behind IP addresses in an effort to determine their state, e.g. up or down. Second, it uses the server state information to automatically update the IP address associated with a particular DNS record, such as an ‘A’ record, ‘AAAA’ record or otherwise. It may consist of other components designed to deliver email or SMS alerts in the event that an outage is detected or changes are made, but any successful DNS Failover solution must consist of at least the first two essential elements.

    Common Applications for DNS Failover

    So now that we know what DNS Failover is, what is the most common use for it and what applications can benefit from this method of automating DNS updates?

    Perhaps the most obvious use that comes to mind is to control web traffic. Failing over between redundant web servers is a very common implementation, and is probably the most frequently used application. From the failover system’s perspective, it really doesn’t matter where the two IP addresses are, so long as they are different. So because of this, it could be used to failover between two different servers at the same datacenter, servers at different datacenters (even across the globe) or it could be even the same server with two different network connections, each having their own IP address, for example a server at a corporate office with one IP on each of two different T1 lines.

    Naturally, what can be done for web servers can also be done for mail servers, FTP servers, streaming media servers or VoIP servers, just to name a few. Essentially, if it has an IP address and can be monitored externally, DNS Failover can route traffic to it when it is up, and redirect to another server when it is down.

    Common Features

    Most well thought out DNS Failover implementations should have at least a few basic features. First, and probably paramount to failover success, is monitoring. The more advanced the monitoring feature-set, the better. This allows you to detect outages as accurately as possible. At a minimum, we would expect functionality to fine-tune the monitors and to run them from multiple geographic locations in order to create an accurate picture for when failover actually needs to occur. Of course, it should probably go without saying that the monitoring and alerting functionality should be able to send alerts via email, SMS or both.

    Another important feature, in our opinion, is some flexibility in how traffic is routed. The most common traffic routing configurations are sequential or round-robin. Sequential allows you to list servers in the order you want traffic to be delivered so that if the server with a priority of 1 goes down, it sends traffic to the server with a priority of 2 and so forth. Round-robin publishes a DNS record for every one of the active and available servers so that traffic is distributed amongst them as evenly as possible. When one goes down or becomes otherwise unavailable, it is simply removed from the pool allowing traffic to continue being distributed amongst the remaining server(s).

    And finally, you’ll probably want a feature that prevents the automatic re-announcement of a server’s IP address when it comes back online. In the case of a server providing static web content, re-adding may not pose a problem, but in the case of a database server requiring resynchronization, this little feature is critical.

    Limitations of DNS Failover

    The biggest limitation when using DNS Failover for application switching is the ability to quickly detect an outage and make a change that will actually propagate the Internet in relatively short order to seamlessly redirect users, both current and future. Even the best DNS Failover solutions that accurately detect an outage and update DNS quickly and accurately still leave customers at the mercy of a well known problem called caching. This is an extremely tough issue to resolve because it is not within the DNS Failover service providers control.

    Caching issues are created when ISPs ignore TTL values, or they can be caused by something as simple as default Internet browser settings which are configured to cache images in order to improve page load times. The shortest compliant TTL value is 60 seconds, and for some ISPs this is simply too short. AOL, for example, is known to ignore low TTL values and substitute them with something much higher, say 15 minutes, for example. But other than those ISPs who ignore TTL values, a 60 second setting in theory *should* propagate the Internet relatively quickly.

    Is there anything better?

    Depending on your application, Cloud Load Balancing might be a better fit. That, of course, should be dictated by your specific requirements for uptime, flexibility for balancing traffic among servers and how critical the need to avoid caching created by TTL avoidance or just plain old browser settings. Cloud Load Balancing is similar in design, but offers extremely powerful traffic management solutions similar to hardware load balancers (except on a global scale) for serious online organizations.

  • Repairing your cracked damaged lcd screen display on Sony Xperia Z3 using original genuine products

    Phones these days get bigger and bigger, more complex and often easier to break. If you drop your phone there is always a chance of breaking your lcd screen display. The ideal solution is not to crack your display by dropping your phone but of course it can happen sometimes unfortunately. If you have the misfortune of breaking your screen then many people assume it will be an incredibly expensive job to repair your phone with an authorised Sony Xperia authentic screen. This is simply not the case if you do a DIY do it yourself repair. Is this possible for the average joe is a very often asked question.. The answer in general is yes. There are many youtube videos and disassembly instructions to help you in the repair. It’s a simple case of unscrewing your phone and swapping over everything.

    Why, you may be thinking is it important to use an original authentic display and not some Chinese copy screen? The answer is very simple, Chinese displays are of a poor quality which often breaks after a small period of time as they use previously damaged and repaired parts. What’s more they don’t have gorilla glass on the front of the display so they break incredibly easy and you end up paying double in the end. The answer is to buy an original display and get your phone fixed back to the factory standard as new. Black, white, green, orange red, or green makes no difference, all the displays are the same when sourced from Sony.

    Now you understand what you need and why, you are probably wondering where can you buy your new mobile phone parts and Z3 Compact from at a cheap good price whilst making sure that you really are buying an authentic supplied by Sony UK product? Well with 14 years of supplying genuine original displays your honest supplier of choice could be original mobile parts who buy directly from Sony. Good luck with your repair, buy original and save money with the cheapest repair getting it done properly the 1st time.

  • The Path To Finding Better Keys

    The Importance of Finding a Licensed Locksmith Company

    It is important for you to realize that there are so many things that people are designed to do for themselves. Each task is actually very crucial for people to do in order to help certain people along the way.

    Locksmiths are one of the many people who are able to address all the concerns that you have. There are so many instances in which you would tend to forget bringing the keys of your car and even of your house because of being distracted. Since you have an idea of how important it is for you to get the best locksmith that you need, you have to make sure that you know where this person can be found. You do not have to worry about getting a good locksmith because there are locksmith companies that can certainly help you with your needs. It is of great importance that individuals are able to look for a certain locksmith company that is known to be very effective in their jobs.

    Getting the locksmith that you need for the problems that you have can be done with a locksmith company that you have in mind that you can hire. You have to make sure that you are able to have the locksmith that you need with the reliable locksmith company that you have hired. In order for you to be sure that you are getting the right services of a professional locksmith, it is important that you make sure that the person is licensed. When you are looking for a locksmith, it is always better that he is linked to a company that gives them all the credentials that they need. You have to remember that when your locksmith is under the care of a certain company, all the damages that might happen along the way will be insured.

    Feedbacks play an important role for people who would want to assess the services that a certain locksmith can give to them. There is a need for you to remember that having a clearer picture of what locksmith companies can do to people makes you more motivated to hire one. You can also have the option to contact other clients to ask them about the experience that they had with a specific locksmith company. If you want to assess the services of a certain locksmith company, knowing the prices of the things that they offer to you plays a crucial role before hiring them. Since you are aware of the prices that certain services will give you, you are then able to avoid the irrelevant costs that you may have along the way. When you have found the best locksmith company that you need, it would be easier for you to get what you want along the way.

  • Smart Tips For Uncovering Seminars

    Setting the Right Goals and Making them Real

    Everyone should be able to make decisions based on what is important to them and work based on the said decisions. To do so, you need to have goals that are timely and realistic. Having a plan for your daily activities is the sure way to attain success. Here are a few tips that have worked before.

    Goals are important for any person striving to attain a level of self-actualization. These goals will help you create a future that you want for yourself. With goals, chances are that you will work towards specific growth components.

    Differentiate reality from wishes

    Dreams have a way of making people push themselves to achieve more than they would otherwise do. Humans are able to achieve more when their minds are stretched to its limits especially when pursuing something worthwhile no matter how difficult. However, focus on the reality to avoid losing yourself in dreams that may cause you to stagnate. You need to figure out the challenges that must be resolved, work out potential solutions and focus on the desirable outcomes. You need to start by making a single step at a time.

    Know the outcomes to expect

    This is a strategy of setting realistic goals. Knowing the possible result of the goals you are setting is the best way to achieve them. It is important to gauge your progress every step of the way based on the outcome you expect. As such you will have the opportunity to correct any mistakes that will hinder you from reaching an expected outcome.

    Set deadlines

    Everyone can work for as long as they want. However, true success comes when you are able to achieve your goals with a set period. It is important to have time limits that you can use to achieve your goals. Also, these are important for preventing distractions. It helps you get everything in the right perspective.

    Accountability matters

    It is impossible to achieve anything if you are accountable. Set some ground rules and measures that will keep you in line. Come up with severe consequences for deviating from the goal and make sure that it applies to your everyday living. It should be something whose impact is costly to discourage you from making a mistake since this will make you focused on the goal to prevent making the same mistakes. Such dedication will ensure that you are always on course to your greater goal.

    Have the right support

    It is important to have a group of like-minded people say two or three people within your circles. Two or three people with the same desire and goals as yours will help you with collective evidence. You are likely to set realistic goals and pursue them when you have people pushing you to do the same.