Squid_ The Definitive Guide - Duane Wessels [9]
Funding for the IRCache project ended in July 2000. Today, a number of volunteers continue to develop and support Squid. We occasionally receive financial or other types of support from companies that benefit from Squid.
Looking towards the future, we are rewriting Squid in C++ and, at the same time, fixing a number of design issues in the older code that are limiting to new features. We are adding support for protocols such as Edge Side Includes (ESI) and Internet Content Adaptation Protocol (ICAP). We also plan to make Squid support IPv6. A few developers are constantly making Squid run better on Microsoft Windows platforms. Finally, we will add more and more HTTP/1.1 features and work towards full compliance with the latest protocol specification.
Hardware and Operating System Requirements
Squid runs on all popular Unix systems, as well as Microsoft Windows. Although Squid's Windows support is improving all the time, you may have an easier time with Unix. If you have a favorite operating system, I'd suggest using that one. Otherwise, if you're looking for a recommendation, I really like FreeBSD.
Squid's hardware requirements are generally modest. Memory is often the most important resource. A memory shortage causes a drastic degradation in performance. Disk space is, naturally, another important factor. More disk space means more cached objects and higher hit ratios. Fast disks and interfaces are also beneficial. SCSI performs better than ATA, if you can justify the higher costs. While fast CPUs are nice, they aren't critical to good performance.
Because Squid uses a small amount of memory for every cached response, there is a relationship between disk space and memory requirements. As a rule of thumb, you need 32 MB of memory for each GB of disk space. Thus, a system with 512 MB of RAM can support a 16-GB disk cache. Your mileage may vary, of course. Memory requirements depend on factors such as the mean object size, CPU architecture (32- or 64-bit), the number of concurrent users, and particular features that you use.
People often ask such questions as, "I have a network with X users. What kind of hardware do I need for Squid?" These questions are difficult to answer for a number of reasons. In particular, it's hard to say how much traffic X users will generate. I usually find it easier to look at bandwidth usage, and go from there. I tell people to build a system with enough disk space to hold 3-7 days worth of web traffic. For example, if your users consume 1 Mbps (HTTP and FTP traffic only) for 8 hours per day, that's about 3.5 GB per day. So, I'd say you want between 10 and 25 GB of disk space for each Mbps of web traffic.
Squid Is Open Source
Squid is free software and a collaborative project. If you find Squid useful, please consider contributing back to the project in one or more of the following ways:
Participate on the squid-users discussion list. Answer questions and help out new users.
Try out new versions and report bugs or other problems.
Contribute to the online documentation and Frequently Asked Questions (FAQ). If you notice an inconsistency, report it to the maintainers.
Submit your local modifications back to the developers for inclusion into the code base.
Provide financial support to one or more developers through small development contracts.
Tell the developers about features you would like to have.
Tell your friends and colleagues that Squid is cool.
Squid is released as free software under the GNU General Public License. This means, for example, that anyone who distributes Squid must make the source code available to you. See http://www.gnu.org/licenses/gpl-faq.html for more information about the GPL.
Squid's Home on the Web
The main source for up-to-date information about Squid is http://www.squid-cache.org. There you can:
Download the source code.
Read the FAQ and other documentation.
Subscribe to the mailing list, or read the archives.
Contact the developers.
Find links to third-party applications.