User manual HP COMPAQ TASKSMART C SERVER COMPAQ TASKSMART SERVER FOR INTERNET CACHING DEPLOYMENT GUIDE

[. . . ] TaskSmart Server for Internet Caching Deployment Guide Second Edition (August 1999) Part Number 154300-002 Compaq Computer Corporation Notice The information in this publication is subject to change without notice. COMPAQ COMPUTER CORPORATION SHALL NOT BE LIABLE FOR TECHNICAL OR EDITORIAL ERRORS OR OMISSIONS CONTAINED HEREIN, NOR FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING FROM THE FURNISHING, PERFORMANCE, OR USE OF THIS MATERIAL. THIS INFORMATION IS PROVIDED "AS IS" AND COMPAQ COMPUTER CORPORATION DISCLAIMS ANY WARRANTIES, EXPRESS, IMPLIED OR STATUTORY AND EXPRESSLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, GOOD TITLE AND AGAINST INFRINGEMENT. This publication contains information protected by copyright. [. . . ] Any private information should be marked as such by the source server and not be held in cache. Likewise, secure or sensitive data that is transmitted with encryption is not cached. Therefore, use of a firewall to protect the cached data is not a concern. However, some corporate policies mandate that any proxy must be deployed within the confines of a firewall. CAUTION: If you are deploying the TaskSmart C-Series server outside of a firewall, take care to implement proper monitoring and security measures. Additional TaskSmart C-Series server security is invoked by changing the password to a non-default string. Enable logging and closely monitor the server. TaskSmart C-Series servers can be deployed either inside or outside of a firewall. If deployed within, the TaskSmart C-Series Server software has a SOCKS client that can be used to tunnel through the firewall and out to the Internet. In some cases, a firewall may degrade the performance afforded by high-speed cache engines like the TaskSmart C-Series server. If the cache is deployed outside of the firewall, all incoming traffic, both from cache and not from cache, will be subject to the limitations of the firewall. If you are currently using a proxy to control access through your firewall, TaskSmart C-Series servers can be used in conjunction with this existing proxy through either ICP or CERN protocols. Other Proxies and Caches Virtually all modern cache engines are capable of using either ICP or CERN as an inter-cache communication protocol. With these inter-cache protocols, devices work their way through the hierarchy to determine if any local machine contains the requested object. Relationships are established that defines some caches as children and others as parents. Child proxies always ask parent caches for data that is not in the child cache; parents never send requests to children. Proxies can also be defined as ICP peers, where requests can be sent both ways and caches shared. By building this hierarchy, it is possible to deploy a multi-level cache that increases the Web traffic overlap and reduces the maximum amount of wasted WAN bandwidth. If you already have a proxy cache deployed at your network point of access, Internet Caching Protocol (ICP) or CERN provide a mechanism to deploy child caches at departmental aggregation points. 2-8 Compaq TaskSmart Server for Internet Caching Deployment Guide Clustering TaskSmart C-Series servers provide fault tolerance through built-in clustered services. Two or more units may be deployed as a forward or transparent proxy for client acceleration in a clustered configuration. Figure 2-3. Cluster client accelerator As long as one unit in the cluster remains functional, all services handled by that cluster will remain functional; regardless of the number of units that have failed. TaskSmart clustering is provided through a virtual IP address and TaskSmart C-Series servers are assigned to monitor and service requests made to that virtual IP address. A virtual IP address is not actually bound to a physical port, as we are accustomed. One or more machines will simply listen to this address, making sure that the address is still responding to requests. If a member of a cluster detects that a virtual IP address serviced by its cluster is not responding, that server will begin servicing requests sent to the virtual IP address. [. . . ] In addition, the reduced load on the origin server can greatly increase the server's capacity. In fact, the ICS software at the heart of the TaskSmart servers was shown to handle over 100, 000 simultaneous persistent connections as a server accelerator. Unlike the client accelerators, there is no configuration that is required on any server other than the TaskSmart C-Series server. Of course, DNS records will have to match your deployment strategy; that is, if you assign the server accelerator the IP address to which DNS, your web server will need a new IP address. NOTE: If you choose not to change the IP address of your web server, you will need to update the DNS entries to redirect requests to the cache. Just as with the client accelerators, other network devices will play a role in determining where a server accelerator should be deployed. Using with a Firewall For a publicly accessible web site, at least one machine must be outside of the firewall in the public domain. [. . . ]