Improving Performance - Reverse Proxy cache (
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Reverse Proxy caching is used by enterprises when dealing with static, unsecured Web content. Reverse proxy caching is deployed in front of the web server for external user access. Requests for content to an internal Web server are filtered through the Reverse proxy cache before they reach the source Web server, thereby offloading traffic to the web server. Reverse proxy caches, which store the frequently requested data, are optimized to serve Static data quickly.
When a client browser makes an HTTP request, the DNS will route the request to the reverse proxy machine, not the actual web server. The reverse proxy will check its cache to see if it contains the requested item. If not, it connects to the real web server and downloads the requested item to its disk cache. The reverse proxy can only server cacheable URLs (such as html pages and images). Therefore, Reverse proxies are ideal for caching unsecured, static content.
Server-side caching
Dynamic content caching
As content becomes more dynamic, powerful Web servers are required to handle increasing user demands. Additionally, bandwidth capacity continues to grow as businesses move more and more of their applications on-line. With these ever-increasing needs, server-side caching emerges as the best response to the tremendous performance and scalability requirements of the modern-day Web site.
The simple technique of dynamic content caching can improve both Web site performance and scalability quickly and efficiently, by executing only necessary code on the Web HTTP server. A specifically designed filter between the server and the client caches the output of dynamic requests. Once the PHP code is executed and the HTML result is available, it is saved to the Web content cache. The cache filter detects subsequent requests to the same dynamic page and immediately responds with the cached output before these requests arrive at the Web server. The benefit is three fold: (1) Clients can receive requested HTML files much faster, (2) The Web server does not need to repeatedly execute the dynamic request, saving processor cycles for more productive work and (3) Reduces the amount of database queries executed, conserving overloaded resources.
Figure 2 - Dynamic Content Caching
