Application Delivery (ADX)

Transparent Cache Switching 101 with ServerIron

by pmorrissey on ‎07-12-2009 10:20 PM - edited on ‎10-31-2013 03:32 PM by bcm1 (1,770 Views)

Transparent Cache Switching with ServerIron

 

Feature Brief Intro

 

Transparent Cache Switching (TCS) allows a ServerIron ADX to detect and switch web traffic to local cache server(s) within the network. Cache servers process web queries faster and more efficiently by temporarily storing details about repetitive web queries locally, reducing the number of external inquiries required to process a web query. By limiting the number of queries sent to remote web servers, the overall WAN access capacity required is lessened as is the overall operating cost for WAN access. ServerIron increases the reliability of transparent caching within a network by supporting redundant web cache server configurations known as web cache server groups, as well as supporting redundant paths to those server groups

 

How it works:

 

Figure 3.4 shows a configuration in which HTTP traffic flows into a Point-of-Presence (POP) from remote access servers (RASs) and out of the POP to the Internet through a Border Area Router (BAR). The cache servers are labeled C1, C2, and C3.

 tcs.png

 

In the most basic setup, HTTP traffic flowing across the ServerIron, in any direction, is redirected to the cache servers. If a cache server has the requested content, the server returns the content to the client. If the cache server does not have the content, the cache server goes to the Internet to get the requested content, then caches the content and sends it to the client via ServerIron. The hashing feature of TCS allows ServerIron to spread the traffic across the caches, ensuring similar requests go to same set of servers and minimizes duplicate data on the cache servers.

 

#Admin Manual Links:-

 

 

Popular Features/Options

Cache Route Optimization : The Cache Route Optimization (CRO) feature solves a typical network topology dilemma, in which a cache server’s default gateway is not the most direct route to the client. More..Cache Route Optimization

 

Policy-Based Caching: Normally, IP filters control whether the ServerIron redirects web requests from certain hosts or for certain sites to a cache server or sends the requests to the live sites on the Internet. Policy-based caching enables you to use IP filters to selectively cache some web sites but not others, on specific cache servers. More..Policy-Based Caching

 

Fastcache: Traffic in typical TCS configurations passes through the ServerIron both from the client to the cache and from the cache to the client. The ServerIron uses the cache responses to the client to diagnose the health of the cache server. You can override this behavior by enabling the FastCache feature. This feature configures the ServerIron to continue redirecting client requests to a cache server even though the ServerIron does not see responses from the cache server. More…Fastcache

 

Proxy Server Cache Load Balancing: Proxy Server Cache Load Balancing relieves clients who have configured their web browsers to point to a proxy server from the need to reconfigure their browsers. When you configure the ServerIron for this feature, the ServerIron performs TCS for clients whose browsers do use a proxy and for clients whose browsers do not use a Proxy. More …Proxy Server Cache Load Balancing

 

Content Aware Cache Switching : Content aware cache switching uses information in the header of an HTTP request to determine how or if content should be retrieved from a cache server. Using the text in a URL string/http header, the ServerIron sends a request from a client to a cache server or to the Internet according to user-defined policies. More…Content Aware Cache Switching

Contributors