Web caches are temporary stores of website-related data such as documents, images, and other website media. They are used to reduce network traffic and satisfy network requests more quickly and efficiently. Web caches may be hardware or software implemented solutions.<\/p>\n
Web caches temporarily store data from remote hosts such that local client requests can be satisfied by relying more on local resources than outside network resources<\/a>. A web cache server sits between client requests and host responses and is designed to limit the number of connection requests passed along to the remote server.<\/p>\n In HTTP connections, a client sends a request to a remote host. Assuming all goes well, the host responds with the requested data which is then transmitted back to the client. Web caches are configured to pass client requests along to hosts, receive the response data from the host server, and then pass that response data back to the requesting client connection.<\/p>\n During the process outlined above, the web cache server stores a local copy<\/strong> of the response data into local storage. If that data is then requested again by another local client connection, the web cache server can respond to the client directly, rather than having to forward the request to the remote server.<\/p>\n Web caches offer two primary benefits:<\/p>\n As an example, consider a local ISP having configured a web cache server to service their local residential clients. One customer could use their Internet browser to send an HTTP GET request<\/a> to The GET request would first pass through the ISP’s web cache server and check to see if a copy of that webpage exists in local storage. After determining that no such copy exists, the ISP’s cache server would then forward the request<\/a> to the Upon receipt of the HTTP GET request from the local ISP’s web cache server, the Now let’s consider the scenario in which another customer from a different home sends an HTTP GET request to the However, this time the ISP’s cache server will already have the response data from the last time it connected to the The above example illustrates how web caches can help reduce network delay time and also reduce the resource consumption of access network links. In that scenario, one very important consideration was omitted; what happens when the pbs.org host updates its data?<\/p>\nBenefits of Web Caches<\/h2>\n
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pbs.org<\/code> to see if there are any new articles or media posted.<\/p>\npbs.org<\/code> server.<\/p>\nLocal Storage<\/h3>\n
pbs.org<\/code> server would then send response data back to the ISP cache. Upon receipt, the ISP’s cache server will store a local copy of that data and also respond to the original customer’s request with that data.<\/p>\npbs.org<\/code> server to check for the latest articles and media. That request will also be directed to the ISP’s web cache server.<\/p>\nReduced Network Traffic<\/h3>\n
pbs.org<\/code> server. In this scenario, the ISP cache server will respond directly to the customer request with the correct response data\u2014often cutting down on customer-perceived network delays\u00a0significantly<\/em>.<\/p>\nCache Expiration<\/h2>\n