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what is the advantage and the disadvantages of client pull and server push in Web Technology? please tell because I can\'t get the satisfactory answer in the Internet.
Administrator
on 2010-11-23 10:30:00Traditional Web browsing has been based on the model of \'pull\' - wherein, when a user requires information he visits the website thereby making a request and the browser \'Pulls\' or downloads the information into his computer. A new form of information delivery called \'push\' is rapidly gaining popularity. \'Push\', in fact, amounts to pull and push, pull out relevant information from a large number of sites and push into computers of individual clients. The information can be made available to viewers just like television broadcast media except that the viewer \'subscribes\' to his channels of interest. Information is then sent regularly to his system. The technology uses client-server software of varying degrees of sophistication. The advantages are several : * It cuts down on browsing time, particularly for those who have low - speed connections. * It enables a client to know when updates have been made to their favorite sites, because notices of these are sent out via e-mail. * Channels offered by \'push\' developers could be seperate ones for news, weather, sports, softwares and so on, so it lets you select channels that deliver focused content.Focused content here means, the user is given hyperlinks only to selected news. * Advertisers & Ineternet Programmers listen !!! Server can authoritatively push advertisements and make sure that Client has to view all those advertisements while receiving genuine information in background from Server. This can be achieved either by displaying those advertisements in Client\'s window, or by inserting the same in pushed information. * The big disadvantage is that the more push players there are, the more it increases Net traffic. push companies send out crawlers to check websites for updates, and these can be a factor for congestion on the net. The mechanics of push-pull : How it works? Surfers find it quite annoying to reach for the \'reload\' button every time transfer is interrupted. Web pages with dynamic content is another reason to refresh pages at the client end. push-pull technology seeks to solve this problem by periodically downloading pages to the client. There are two ways of doing this : \"Client-pull and Server-push\". With client-pull, the change is instigated from the Web client end. After a certain period, (usually defined within the Web page), the browser requests a page again, during which time elements on it may have changed, causing the displayed Web page to evolve. Included with the data is a directive that might say, \'reload this data in 10 seconds,\' or \' go load this other URL in 20 seconds.\' After the specified amount of time has elapsed, the client does what it was told to do in the directive (reloads or goes to another URL.) . The browser automatically displays the reloaded data or new URL. Alternatively, server-push can be used. In this , it is the server that determines when things change, and simply sends down the new data. This method can be more efficient , since new HTTP connections don\'t have to be opened all the time. The downside is that the open connection consumes a resoruce on the server side while it\'s open (only when the server knows it wants this to happen, though). Although at first glance these might seem very similar, there is a fundamental difference. With client-pull, the connection is closed after each transfer in the normal way. The client is told when to open a new connection, and what data to fetch when it does so. But with server-push, the connection is left open so that the server, whenever it wants, can send more data for the client\'s browser to display. The process continues to repeat itself with the connection remaining open and the server sending new information periodically. Now the client is able to surf the internet from the local disk.
Soumya
on 2010-11-23 10:30:00Thank you for your kind reply, but I am looking for a brief answer and expecting from the administrator, but it is alright, if you found any other answer which is briefer than this then please post it....Thank you...