Open source software is finding its way into server rooms of all types and sizes. For those that have yet to get their feet wet, we outline the basics and highlight the options.
Much fuss has been made about open source software, particularly its influence on back-end server environments. At this point, no one will deny that open source software is becoming fairly pervasive.
As of March 2006, for example, the open source Apache Web server powered nearly 69 percent of all Internet Web servers, according to the oft-cited Netcraft Web Survey. In addition, shipments of Linux-powered servers grew 20.8 percent in 2005, according to IDC, and the market research firm predicts Linux will account for 29 percent of server shipments in 2008. In practice, Linux penetration is probably even higher, as many installations are do-it-yourself affairs without a commercial vendor attached.
Although analysts and other agenda-driven interests have published conflicting data about the costs of open source vs. commercial platforms, at a minimum open source provides options. And, considering its advancing uptake rate, at least some organizations are deciding that open source is the right option for them.
Understanding Open Source
One common misconception about open source software is that it is always free. Indeed, there is a large body of cost-free open source software, including the Apache Web server. But there is no prohibition on commercial businesses creating and selling open source software or, in many cases, modifying and selling existing open source software. Frequently, licensing terms for Free and open source software (FOSS) projects require vendors make modified versions freely available. In such cases, service and support for the "freely available" software is available for a fee.
So although open source software may often be free, lack of acquisition cost is only one attraction. Source code for open source software is available for examination and modification, thus lending open source to customization. Software bugs can be found and patched more quickly, by the client or the vendor. And security may be enhanced because lapses or back doors can be found and repaired by any party. Some people, however, would argue that open source security is compromised for the same reason hackers can scan the code for weaknesses.
Making an Assessment
To best determine whether some or all of your server infrastructure is a good candidate for open source solutions, consider several criteria.
Who is your audience? Does your server infrastructure serve highly platform-dependent users? For example, a Microsoft Exchange server handling groupware messaging for a shop full of Microsoft Outlook clients is serving a highly specific audience. Unless your plans include migrating clients to open source messaging solutions, such as Gnome Evolution, the MS Exchange server probably makes the most sense in this scenario.
On the other hand, many "generic" network services, such as file serving, POP3 or IMAP4 e-mail, Web serving, DNS, CUPS-based printing, and even some databases can be served neutrally by open source packages. In a neutral network, client connections may come in from any platform with support for these protocols. POP and IMAP e-mail is supported by virtually every e-mail client available, so running an open source e-mail server does not preclude which clients it can serve.
A third consideration is cost control and cost shifting. Traditionally, commercial server solutions require ongoing licensing fees be paid for the right to use the software. These fees may include a certain level of support, which can often be upgraded with additional payment. This may also introduce the need for in-house expertise to maintain the server infrastructure, thus raising costs.
Open source server solutions can offer more financial options. With money invested in in-house expertise, outside support costs can be low to none. This same expertise can customize open source software to a degree that may be costly or unavailable with commercial server applications. Third-party vendors, like Novell and Red Hat, offer subscription-based open source solutions that function similarly to commercial offerings, involving ongoing costs with support and maintenance contracts. In this scenario, the costs may not differ all that much from those of commercial applications. Enterprises, however, may continue to benefit from other flexible aspects of open source software.
>> Options Abound
Open Source Choices
Because open source solutions can be packaged in many different ways, the options may at first seem overwhelming. Your major decision will be whether to embark on a "roll your own" open source solution using in-house expertise or an outside consultant, or invest in a turnkey open source solution from a major distributor.
For example, Red Hat Enterprise Linux (RHEL) ES for "entry-level and departmental" workloads starts at $349 per year. It comes with 30 days of phone support and one year of Web-based support. Higher-priced packages are available with more support. With an RHEL ES system, most office server functions are ready to go, including file, Web, mail, and print serving. Red Hat's Enterprise Linux AS starts at $1,499 a year. It is oriented toward larger enterprise applications and adds database, CRM, and ERP functionality.
Novell's competing turnkey open source server platform is SUSE Linux Enterprise Server (SLES) 9. Like Red Hat's entry-level offering, SLES begins at $349 per year and goes up from there, depending on the hardware configuration and support package selected.
Both Novell's and Red Hat's offerings are out-of-the-box packages that bundle and configure various individual open source applications to build a feature-complete server environment. In addition to their support, each vendor has also developed its own software management and configuration tools as "value added" features.
Alternatively, all of the open source software bundled in these turnkey solutions is freely available. Because their setup, configuration, and operation requires a solid level of expertise, rolling your own open source solution is often not as easy as simply downloading the software and clicking "Install." But, with an experienced hand inside or outside your organization, most of this software can be set up quickly and without the ongoing costs of yearly subscriptions.
Let's get specific. What open source applications are needed in a typical data center?
|PHP 4 or 5
||Dynamic scripting language for Web applications|
|MySQL or PostgreSQL
|Jakarta and Tomcat
||Java ServerPages and Servlet support for Web applications|
|Sendmail or Postfix
||File server compatible with Windows shares|
||Common Unix Printing System Cross-platform print server|
||(LDAP: Lightweight Directory Access Protocol) cross-platform user authentication|
||Secures Web serving|
||Instant messaging server|
Even a single server equipped with the above open source software can power many, if not most, office needs. But these represent only the tip of the iceberg. Many more-sophisticated configurations can be put together with open source software, including large server clusters and bridges between open source applications and the more popular commercial servers.
Whether your organization is large or small, integrating open source solutions into your server infrastructure does not require an all-out commitment right from the start. In general, open source software will "play nicely" with existing solutions, enabling you to test and integrate over time or jump in with both feet whichever is most appropriate.
To cut through the myriad and sometimes confusing options, the initial decision should be broken into three choices:
- Roll your own using freely available resources.
- Rely on an in-house expert or external consultant to get you started with one or more open source servers.
- Go all-in with a turnkey annual subscription solution, such as those from Red Hat and Novell.
To embark on No. 1, you'll likely want to find a Linux distribution that is both comprehensive and oriented toward do-it-yourself solutions. Dozens of Linux distributions are available, but those best positioned for the server room include Debian, openSUSE (a cost-free spin-off of Novell's SUSE Linux), and Red Hat Fedora (the cost-free spin-off of Red Hat Linux). These free open source distributions will include most of the server software you need (and almost anything else is available for download), but lack the value-added features of their commercial siblings, including vendor support and priority updates and patching.