Seymour Cray didn't like virtual memory and has been quoted as saying: “Memory is like sex; it's better when it's real.” Whereas Paul Barry (LJ March 2002, Letters) apparently wasn't aware of Seymour's quip, Linus certainly was; his comment comparing software to sex is an obvious allusion. Perhaps it's not that Linus needs to choose his words more carefully; perhaps it's that authors should explain the literary significance of these words for the younger generation.
After spending a few nights with LJ [see David Bandel's “Taming the Wild Netfilter” in the September 2001 issue, available at /article/4815] at hand's reach to configure my firewall, I came across the URL www.boingworld.com/workshops/linux/iptables-tutorial. This is to me the best source I have found on Netfilter. I believe the reference to Rusty Russel's document is a tribute to Rusty's own work, but the document is not usable for a basic user like me, a simple, average Linux user! Please to advertise this URL to your user if they have troubles using the wild, wild Netfilter.
For more on Netfilter, see David Bandel's more advanced article “Netfilter 2: in the POM of Your Hands” in this issue.
Gary Bickford's letter in the February 2002 issue of LJ states: “GTO is an acronym (Gran Turisimo Omologato), which according to AltaVista means 'great accredited tourism', which I suspect doesn't express the flavor of the phrase.”
He's right—Gran Turisimo refers to a racing class (Grand Touring, or GT) of cars, and Omologato (“homologated” in English) refers to the particular group of cars that was built specifically to fulfill the racing organization's requirements. As it turns out, Ferrari cheated on this; they never actually built the number of cars they were supposed to, but the organization never called them on it.
Most Pontiac dealers, when asked where the GTO moniker came from, were at a loss to explain any of this when the acronym was tacked onto the 389-engined version of the Pontiac Tempest.
I found a small problem when using the caching PHP file [see Bruno Pedro's “Improving the Speed of Web Scripts” in the March 2002 issue of LJ]. The md5 hash is generated by using the PHP_SELF name of the called PHP script. But what if I generate content depending on the query string? I changed from PHP_SELF to REQUEST_URI, so it generates a unique cache file per unique parameters. This way I saved 90% execution time compared to running against my MySQL data sources.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.View Now!
|The Firebird Project's Firebird Relational Database||Jul 29, 2016|
|Stunnel Security for Oracle||Jul 28, 2016|
|SUSE LLC's SUSE Manager||Jul 21, 2016|
|My +1 Sword of Productivity||Jul 20, 2016|
|Non-Linux FOSS: Caffeine!||Jul 19, 2016|
|Murat Yener and Onur Dundar's Expert Android Studio (Wrox)||Jul 18, 2016|
- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- SUSE LLC's SUSE Manager
- Managing Linux Using Puppet
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Parsing an RSS News Feed with a Bash Script
- Google's SwiftShader Released
- Doing for User Space What We Did for Kernel Space
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide