Webcasting refers to the process of broadcasting the web content to the internet users regularly. For this purpose the Channel Definition Files, popularly known as CDF are used. These files are very important while creating the Active Desktop components. The type of content, its update interval and the amount of content to be uploaded and downloaded is specified in the CDF file.
Channel designing is a very important task. A properly designed channel is easy to manage, user friendly and have lots of exciting features.
Below are some tips and guidelines which can be followed in order to create a captivating online channel:
- If the channel contains large amount of content then it must be managed in a hierarchy and the Top Level should be very attractive yet simple. There should not be too much content at the top level. It should only contain the logo and main information about the channel.
- Keep the navigation between different levels as simple as possible because if it is complicated and uneven then the user will get confused and will not be able to find out particular information.
- In order to make the channel look more attractive you can make use of Dynamic Hyper Text Markup Language (DHTML) tools.
- One of the most important features which should be included while designing the channels is offline browsing. There may be chances when the user tries to browse the web page offline. During this phase many Java applets and Active X controls don’t work properly, especially the dynamically loaded images. Therefore the channel must be tested completely for offline browsing.
- Instead of stuffing a single page with loads of information provide the content in small chunks distributed over different pages. There are two main reasons behind this. First is that while surfing the internet the users browse one page after another very quickly and do not take interest in reading those web pages which are poorly designed and contains lots of textual information. Secondly, if the channel contains lots of information it will take more time to get loaded in the web browser. Therefore the channels should be as slim as possible so that they can be loaded with a snap otherwise the user will not wait for it and switch over to some another channel.
- In order to ensure scalability, uniformity and style it is recommended to use Cascading Style Sheets (CSS) while designing the webcast channels.
- To make channels arrest the viewer’s attention at the first glance it should be rich in multimedia. Apart from the textual data pictures, animations, videos, sound effects etc. should be used. Again it should be noted that the multimedia elements should not be used too frequently as it will make the web page heavier to load. The channel developer should intellectually balance the technical qualities and the visual quality of the channels.
Once the channel is properly designed it can be made more interactive and real time component with the help of CDF files. CDF files trigger the regular updates. The developer can also use the CDF files to log the hits to his channel.
Network Attached Storage, popularly known, as NAS is a file storage technology, which is used to store and manage large amount of data in a network, which can be retrieved by the clients whenever needed. It is being used in a large number of organizations now a days because of its awesome benefits.
By implementing NAS an organization can achieve the following:
- Reduced IT Staff Cost: As a NAS server can be accessed via TCP/IP network in graphical user interface (GUI) mode it does no require too many IT professionals for its management and configuration. In this way the IT staff cost is reduced to a great extent. The NAS server can be easily managed with the help of a web browser. The NAS filer is also preconfigured to facilitate specific file serving needs and thus its administration is simplified and there is reduction in the chances of operational errors too.
- Scalable without any Downtime: Business is dynamic in nature and the IT technologies are being designed in a way that they support the expansion or reduction in the current IT infrastructure easily without affecting its operational capability. NAS is also fully scalable. You can install a new filer in just 15 minutes without shutting down the whole NAS server. Advanced NAS servers also support some additional features like storage on-the-fly which eliminated the need for adding another node in the network. The users can simply access the any authorized data whenever they want. Thus NAS is also considered as a real time application.
- Specialized NAS Server: NAS servers are different from the general purpose servers. They have high computing speed and data read/write capabilities and the latency period is very less. NAS servers are optimized to handle a large number of requests simultaneously. They manage a massive amount of data with ease.
- Multi-OS Connectivity and Data-Sharing: One of the exciting advantages of Network Attached Storage is that it supports multiple operating systems and networks. NAS servers support a variety of protocols and file systems such as NFS of UNIX and CIFS of Microsoft Windows. This ensures that you can retrieve and share data on a cross-functional platform.
- Easy and Transparent Backup: The backup of the NAS filer can be taken without affecting the performance of the general purpose application servers.
- The existing network infrastructure can also be leveraged with the help of NAS. You can make better use of the current network and administration skills. Network attached Storage can be deployed anywhere in the network whenever needed without affecting the existing IT infrastructure. It can be easily amalgamated with the large and sophisticated enterprise management tools such as Microsoft Management Console (MMC), Tivoli, HP Openview etc. NAS also supports remote storage and centralized data management. You can store your data in a NAS server placed at a remote location and can manage it over the TCP/IP network from anywhere, even sitting at your home. No doubt, after implementing NAS anyone can reap higher performance from his IT infrastructure.
As discussed earlier, a cache proxy server is the one which stores the HTML documents and other web resources in its own storage space so that they can be delivered to the client without any delay.
Types of Caching
Caching can be passive as well as active. In passive caching the cache proxy server stores the web resources each time the client requests it. First of all, the cache server looks into its own database to check whether the requested resource is there or not. If it founds the desired data then there is no need to contact the web server and the data is delivered to the client instantly. If the proxy server doesn’t get the requested resource in its own database then it retrieves it from the relevant location on the internet and saves it for the future reference.
In active caching the cache proxy server stores and updates its database during its idle time. Whenever the cache server is not accessed by the clients for a set duration it learns the most frequently used resources, downloads them via internet and finally saves them in its cache for future reference. During the process of active caching the proxy server also checks for any updates regarding those resources which are already there in its database.
Challenges in Caching Process
No doubt that the cache servers incredibly reduce the latency periods and facilitate smooth data transactions, but the file caching process faces great challenges. This is not at all an easy task because the resources that have been saved in the cache server are static in nature but the web is highly dynamic and unpredictable. Sometimes a web page remains same for a long period and suddenly changes and sometimes changes are made every day. In case of real time applications such as sports and news web sites the updates are being done every second. So the cache server gets really into trouble while keeping all its records up to date so that the client doesn’t miss any single bit of information.
A large number of heuristic methods have been evolved till now and are being improved continuously in order to make the file caching more reliable and efficient. Sophisticated technologies are being implemented so that the cache server can keep its database up to date by updating the web documents and deleting the stale/expired records.
Load Balancing the Caching work
The caching can be done by implementing more than one cache proxy server and operating the whole array simultaneously. This benefits the organization in the way that the work load of caching can be shared among all the proxy servers. Thus, the caching can be done more effectively and speedily. This also increases the storage space to be used for storing HTML documents and other web applications. The whole array of cache servers can also be configured in such a way that if one cache server fails, then the remaining ones provide fault tolerance just like the Redundant Array of Inexpensive Disks (RAID).
