Load-balanced Caching Proxy clusters

To provide more advanced caching functionality, use Caching Proxy as a reverse proxy in conjunction with the Load Balancer component. By integrating caching and load-balancing capabilities, you can create an efficient, highly manageable Web performance infrastructure.

Figure 4 depicts how you can combine Caching Proxy with Load Balancer to deliver Web content efficiently even in circumstances of high demand. In this configuration, the proxy server (4) is configured to intercept requests whose URLs include the host name for a cluster of content hosts (7) being load-balanced by Load Balancer (6).

Figure 4. Caching Proxy acting as proxy server for a load-balanced cluster
The graphic that appears here depicts the proxy server acting as a surrogate for a load-balanced cluster

When a client (1) requests file X, the request crosses the Internet (2) and enters the enterprise's internal network through its Internet gateway (3). The proxy server intercepts the request, generates a new request with its own IP address as the originating address, and sends the new request to Load Balancer at the cluster address. Load Balancer uses its load-balancing algorithm to determine which content host is currently best able to satisfy the request for file X. That content host returns file X to the proxy server rather than via Load Balancer. The proxy server determines whether to cache it and delivers it to the end user in the same way as described previously.