Configure an upgradeable Web caching scheme for the enterprise

Web caching helps optimize performance and save bandwidth, no matter how large the enterprise is. And if you choose the right caching solution, it can grow with the growth of your corporate network without costly and time-consuming rebuilding.

Web caching provides a better way to put access objects on an Internet Web server than to keep Web pages and objects that require frequent access in a system closer to the user. The speed is speeded up when accessing these objects again.

A few years ago, the theory was that hyper-bandwidth Internet connectivity would make Web caching useless, but that's not the result. Performance is still a problem even if the fastest rate reaches the 30-45mbps fibre Internet connection and the speed is still slow compared to the 1 Gbps rate LAN. In addition, caching improves availability because cached object copies are still accessible even when the managed Web server is down or unreachable due to network problems. Caching can also reduce the cost of Internet connectivity if the enterprise pays for traffic. Caching is beneficial even for small companies, and a good caching solution will be upgraded with the enterprise level. (Computer science)

Caching Concepts

This is the two main web caches:

Direct caching, which saves copies of Web objects that users frequently access from Internet servers to the enterprise local network.

In reverse caching, a copy of the Web object of an enterprise's internal Web server is kept on a proxy server at the edge of the enterprise network to improve the performance of the external access to the enterprise site.

The Web cache can be configured according to different levels:

Local cache: Saves a copy of the Web object cache on the local computer. Most popular web browsers retain a cache of previously accessed objects by default. For example, Internet Explorer is called a "temporary Internet file." Local cached copies are only useful when users frequently access pages from the same machine.

Proxy caching: A proxy server is a separate machine that caches Web objects for multiple user/client computers within a company. They are computers that are located between the client and the managed Web server, and they are more efficient than the local cache because cached copies are available to any other user/computer that wants to access the object when any user or computer on the enterprise local network accesses it. You do not need to download it again on an Internet server. Proxy caching can be used in conjunction with firewalls at the network edge.

Microsoft's ISA Server, like Bluecoat's tools, includes both firewalls and caching proxies. The caching server can also be a stand-alone machine that runs free caching software or commercial products, such as:

The Linux version of Squid free caching agent

Mows based on Java distributed web and caching servers

Vicomsoft rapidcache Server for Windows or Macintosh

WinProxy for Windows
Upgradeable Cache Solutions

As the company expands, a single Web caching server may not be able to handle all traffic or store enough Web objects. In this case, you can extend the cache solution to establish a caching array-a cache proxy server that works together to allocate the cache load within the group. If a cache server is down, the default capacity is also provided.

To operate in the array, the caching server must be able to communicate with each other using the protocol, for example:

WCCP (Web Cache Coordination Protocol), Cisco caching products, and open source agents such as squid are used.

ICP (Internet Caching Protocol), supported by Squid and bluecoat.

CARP (caching Array Routing protocol), which is used by ISA Server Enterprise Edition to manage the failover and load balancing of cache server arrays.

Carp can support almost unlimited linear scaling to meet the needs of fast-growing enterprises. When adding or removing a server to an array, Carp automatically adjusts and then assigns URLs to efficiently distribute the load.

Cache arrays can be arranged in a hierarchical or distributed architecture. In distributed caching, all proxy servers in the array are in an "equal position" and the load is allocated between them. In a hierarchical cache, agents are configured in chains, and they are at different levels, so servers or arrays are connected to other servers or arrays that are closer to the Internet (the closest servers or arrays to the Internet are considered "upstream", those farthest considered "downstream"). This allows the cached content to be as close to the user as it needs it.

Arrays are highly scalable because you can add servers to the array or increase the array level to a hierarchical architecture without disrupting the current caching solution.

Another scalability issue is the ability to use caching to reduce network bandwidth for branch offices. The branch office agent may not be connected directly to the Internet, but you can use a dial-up connection or a WAN connection to the Office to request Web objects from the upstream proxy server on the head office.

Another option is to provide web-based applications to consumers, using services such as those provided by Akamai. Their Web application Accelerator service optimizes performance in the following ways:

Dynamically map requests to their edge servers and monitor internet routing for transmission on the fastest and most reliable routes.

Use compression technology and prefetching technology (pre-fetching) to minimize bandwidth usage.

Secure the Web transport with secured Sockets Layer (SSL).

Saves web content according to the rules specified by the enterprise.

For special applications such as E-commerce, a solution such as Oracleas Web cache may be considered, which is configured between the Internet and the application Web server, including an Oracle database at the back end.