Archive for category Bookmarks
I deal with computers and large systems on a daily basis and consider myself a pretty knowledgeable guy when it comes to this subject. I do recognize that there are a lot of things that I have ‘heard’ about, but don’t really know much about. One such subject is the whole ‘Wake-on-LAN’ functionality that has been built into computers and operating systems for the last few years, yet remains a mystery to many folks.
Wake on LAN (WOL, sometimes WoL) is an Ethernet computer networking standard that allows a shut-down computer to be booted remotely.
Okay, I know that, but how do I actually implement it?
Today, I came across an article that details exactly how to use this feature on a PC running Windows, or on a Mac. Lifehacker’s feature story titled “Access Your Computer Anytime and Save Energy with Wake-on-LAN” is one of the best primers as to how to set this up and actually use it. I have multiple computers on my home network that go into ‘sleep mode’ when not used for extensive periods of time, and being able to wake them up remotely to use services on them would be of great use to me. And being able to remotely ‘turn on’ a computer that has been shutdown would be of tremendous use, especially for some computers that won’t turn themselves back to their last power state after a power failure.
Yesterday, I posted about how htop was my new replacement for top on all Linux systems I manage. Tonight, while looking through the Google search words that lead people to my site, I found a Google result page which contained a 'hit' that immediately caught my eye. Mike Malone, of the I'm Mike blog had an entry titled 'Top 5 tops: keep tabs on your system'. In it, he describes not only the htop utility I came across earlier, but 4 additional tops to make any Linux administrator smile.
- mtop (MySQL top) monitors a MySQL server showing the queries which are taking the most amount of time to complete. Features include 'zooming' in on a process to show the complete query, 'explaining' the query optimizer information for a query and 'killing' queries. In addition, server performance statistics, configuration information, and tuning tips are provided.
- Apachetop is a curses-based top-like display for Apache information, including requests per second, bytes per second, most popular URLs, etc.
- iftop does for network usage what top does for CPU usage. It listens to network traffic on a named interface and displays a table of current bandwidth usage by pairs of hosts. Handy for answering the question "why is our ADSL link so slow?".
- htop, an interactive process viewer for Linux
- atop is a performance monitor that can display:
- Resource consumption by all processes
- Utilization of all relevant resources
- Permanent logging of resource utilization
- Highlight critical resources
- Watch activity only
- Watch deviations only
- Accumulated process activity per user
- Accumulated process activity per program
- Disk and network activity per process
While I use mtop on a regular basis, and have now started using htop, the other 3 monitors definitely look like they're going to be part of my 'tools' for the various servers I manage. iftop and apachetop seem especially interesting to me, given their more specialized monitoring target.
A coworker of mine showed me a small utility he read about on LifeHacker (Manage Processes with htop) this morning. I checked out the htop project site and quickly downloaded the source rpm and built the package and installed it on one of my Fedora boxes at home.
Here’s how htop compares to top, taken straight from the htop project site:
Comparison between htop and top
- In ‘htop’ you can scroll the list vertically and horizontally to see all processes and complete command lines.
- In ‘top’ you are subject to a delay for each unassigned key you press (especially annoying when multi-key escape sequences are triggered by accident).
- ‘htop’ starts faster (‘top’ seems to collect data for a while before displaying anything).
- In ‘htop’ you don’t need to type the process number to kill a process, in ‘top’ you do.
- In ‘htop’ you don’t need to type the process number or the priority value to renice a process, in ‘top’ you do.
- ‘htop’ supports mouse operation, ‘top’ doesn’t
- ‘top’ is older, hence, more used and tested.
All I can say is I’ll probably not use ‘top’ anymore. It’s htop for me going forward…
I'm always on the lookup for a slick way to display a series of images within a webpage. Jonathan Schemoul over at JonDesign has released SmoothGallery 2.0, and it looks very slick. Here's a small quote from his site that sums it all up:
"So, what is so cool about it ?
Unlike other systems out there, JonDesign's SmoothGallery is designed from the ground up to be standard compliant: You can feed it from any document, using custom css selectors.
For now, Jonathan's solution definitely is leaps and bounds ahead of other similar offerings, which either have less features, too many features, or horribly coded.
When doing any kind of web development, I always come across a time when I need to implement some sort of calendar; be it a small ‘applet’ enabling the user to select a date more effectively, or something a bit ‘larger’, displaying something more relevant for certain days.
Jamie over at www.nodstrum.com wrote up some code that can be used as an effective base for many ‘calendaring’ needs most web developers come across. It’s PHP and MySQL, so it should meet the needs of most folks out of the box, but can also be easily ported to another development language.
One word of caution; Jamie makes it clear that his priority was functionality and not security. As such, if you use his code, make sure to apply best-practices in regards to SQL injection, etc.
If you’re interested in how Jamie’s code evolved, check out these articles also on his site:
If all you’re looking for is a simple, elegant date ‘selector’, give DatePicker a look.
I use a MySQL database in most, if not all, my website development projects. In some cases, especially with applications/sites that tend to get a large number of hits (and as such, a greater number of interactions with the database), it’s nice to be able to see what the DB engine is doing, how many threads are running, etc. My tool of choice has been MyTop by Jeremy Zawodny for a couple years now. Recently, it looks like someone wanting to learn some Ajax has decided to port Jeremy’s great tool over to an ajaxified webpage! No need to login to the database server and run mytop in a console anymore; now I can do it straight from a web browser!
One note of caution; the application is written for PHP5. There is a small modification available which will enable the application to run under PHP4. It’s located in the ajaxMyTop forums:
http://ajaxian.com/archives/779 – Ajaxian Review of ajaxMyTop
http://jeremy.zawodny.com/mysql/mytop/ – Jeremy Zawodny’s original mytop webpage
http://sourceforge.net/projects/ajaxmytop/ – ajaxMyTop Project Website
My good friend Scott reminded me of an old site we had found a while back when we needed to whip up one of those browser favicons for a project we were assigned to. A browser favicon is basically that little logo/image you see next to the url when you go to certain sites. It’s also used as the logo when you save any page on such a site as a bookmark.
This online tool enables you to upload any image and it will convert it to the favicon format on the fly. It’s a great timesaver when you don’t want to start from scratch and want to get something you can tweak to your liking.
Finally, someone has taken the time to write a short, concise and to-the-point article that you can point even your parents to in regards to what RSS is and how useful it can be/really is.
Ever have this nagging song or even just this rhythm looping in your head and you have no idea what the song is named? Now you have a chance to find out! By using your keyboard’s space-bar, you ‘tap‘ the ryhthm of the song and the website will search its ever-growing database of songs (currently at over 7600) for a match. Head out to The Song Tapper and try it out. I tried tapping Where It’s At by Beck which has been in my head since I woke up this morning for some reason and the site accurately identified it. Incredible! I love it!
If you’re familiar with what VMWare does (the creation of smaller virtual machines running concurrently on the same computer), then you’ll want to take a serious look at the latest release of the Xen Virtual Machine Monitor. What exactly is Xen, you ask?
Xen is a virtual machine monitor (VMM) for x86-compatible computers. Xen can securely execute multiple virtual machines, each running its own OS, on a single physical system with close-to-native performance.
If you have a few minutes, check out the project’s website and give Xen a try whenever you need to setup any sort of Virtual Machine, either for testing purposes or for some debugging.
I was chatting with a friend this morning when he mentioned to me that he spent part of his weekend rebuilding one of his home computers. He indicated that he was reluctant doing some of the cleanup work because he wasn’t sure where he had packed all his legally purchased software keys; he moved to a new home a couple weeks ago and he has boxes scattered all over the place. I immediately brought up a little tool I have used in the past that has more than once get me out of such a bind. Take a look at the Magical Jelly Bean Keyfinder. Make sure you pickup the Beta version, since the stable version is a little outdated and will not detect keys for Office 2003.
My RSS reader of choice is currently Bloglines; it meets all my needs, is always accessible from any computer/browser I’m using at any point in time, and all the RSS data and fetching processes is conducted by the Bloglines servers. Whenever I can avoid installing another client on any of my computers is a blessing.
Now, if I needed to install an RSS reader, RSSOwl (http://www.rssowl.org) is definitely the client I would use. First off, it’s Open Source and as such is freely available. It’s available for many system architectures I use, such as Linux, Mac OSX, Windows and Solaris, with an emphasis to keep the same look and feel across all of these. The one negative point I have is that being a Java application, it depends on having a properly installed working copy of the Java Runtime Environment (JRE) on the computer you intend to install it on.
RSSOwl has a long list of features:
- Import your favorite newsfeeds using the OPML format.
- Bookmark your favorite newsfeeds in nested categories.
- Import Blogrolls into RSSOwl.
- Built-in internal browser to read news that contain HTML.
- Export the content into one of the formats PDF, RTF or HTML.
- Choose between a 2-column and a 3-column layout.
- A lot of search-options make RSSOwl a powerful application to search inside a newsfeed or an entire category.
- The integrated newsfeed-search engine allows to search for newsfeeds by keyword.
- Simply enter the website containing links to newsfeeds into the feed-discovery and RSSOwl will show all the newsfeeds it has found.
- Place RSSOwl into the system tray on minimization.
- RSSOwl is highly customizable. “Preferences” allow to change fonts, languages, colors, hotkeys and a lot more.
All in all, RSSOwl is the feature-rich reader that will definitely become my stand-alone reader of choice, when the need/time for such a thing comes around in my case. Until then, I remain faithful to Bloglines.