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Generating XML Sitemaps for MediaWiki
August 22nd, 2008 (5 days, 12 hours ago) by Jeff | Permalink | Dump Core
Not long ago, I took advantage of a nifty WordPress plugin to enable XML sitemaps for the blog. For those who’ve never heard of XML sitemaps (I hadn’t for quite a while), they are little XML files in a specific format that give search engines like Google hints on how to index your site. They don’t necessarily improve your search rankings per se, but they help the search engine better decide what to index, when it was last updated, relative priorities of different pages, etc. You then throw a special line into your robots.txt file or directly submit the file to the search engine to let it know the file is available. Once the engine knows about it, it will check it periodically to optimize how the site is indexed.

The plugin, of course, makes this ridiculously easy for WordPress. However, GPF gets orders of magnitude higher traffic than the blog does, so finding a way to generate sitemaps there would be ideal. I toyed with the idea for a while until I finally sat down, examined the sitemap specification, and figured out how to roll my own code. It now successfully runs via cron each morning and gives a pretty thorough census of what’s available on the GPF server. The problem is that the GPF site is divided into several parts that are largely autonomous and self-contained:
- The archive, of course, is the main bread and butter. This is what people come to see, so it is vitally important to get everything represented, especially since the archive is entirely dynamic PHP. I count the main index page as part of the archive, as it displays the latest strip.
- The forum is self-contained because it uses a third-party application: phpBB. I decided long ago to discourage spamming by blocking search engines from indexing the forum, relying on the forum’s internal search capabilities for users who want to find things. Since search engines were being blocked anyway, I decided the forum didn’t need a sitemap; that would just be a waste of processing time.
- The wiki, however, is slowly becoming a vital part of the site. It replaces the old cast pages and adds tons more GPF metadata in a convenient, easily searchable form. I wanted to make sure that got included too. The GPF Wiki runs MediaWiki, the same software that powers Wikipedia. As far as I know, MediaWiki does not include any internal mechanism for generating XML sitemaps nor are there any extensions to do so. (I could easily be wrong, however; I’ll admit my research on this was extremely limited.)
- Then there’s everything else. The GPF site beyond the two pre-packaged items above is completely custom-built PHP, so there’s no one to blame for that mess but myself.
Ignoring the forum, that left me three major sub-projects for creating sitemaps. It’s easy enough to segregate these into separate files and tie them together using a “sitemap index” file, so that wasn’t a problem. The archive would just be a formatted dump of the archive database, deriving approximate update times from the posting date. The bulk of the rest of the site could be done by stepping through the file structure of the site and taking note of every HTML or PHP file and its last modification time (conveniently ignoring certain files and directories that don’t need to be counted, like access-restricted Premium pages). And that leaves the wiki.

I managed to come up with a decent wiki sitemap routine that I thought I’d share, just in case someone else might be interested. Of course, it’s not likely to be useful for massive wikis like Wikipedia—sitemaps are restricted to 10MB in size and 50,000 URLs—but something small like the GPF Wiki would be easy to submit and index. It was built using MediaWiki 1.12.0; I am uncertain what database changes may be needed for older or newer versions. Here’s my current process:

I only want to index relevant pages, including category pages. The relevant database table for this is “page”. (How… convenient). Unfortunately, this table also contains things like redirects and images. Each image has its own “page” assigned to it; try clicking on an image in Wikipedia or in the GPF Wiki to see what I mean. The time stamp of the latest revision, however, is stored in the “revision” table, joined to the page table by the latest revision ID number. So a good starting bit of SQL would be:

select p.page_title, r.rev_timestamp from page p, revision r where p.page_latest = r.rev_id and p.page_is_redirect = 0 and p.page_title not like '%.gif' and p.page_title not like '%.png' and p.page_title not like '%.jpg';

Unfortunately, this also returns a few meta pages like the sidebar and editing pages. Before selecting, I define a look-up hash of titles I want to avoid and as I loop through the results I just skip those.

The title, of course, is both the displayed title and the input portion of the URL that uniquely identifies the page. Thus, knowing the base URL (http://www.gpf-comics.com/wiki/) I can easily reconstruct the public URL of any article from the title. As with Wikipedia links, spaces have already been converted to underscores, but the rest of the string needs to be be URL encoded. This is easy enough, so we can quickly build the full URL as required by the XML schema.

The time stamp is a little bit tougher. MediaWiki stores time stamps as a 14-digit number in YYYYMMDDHHMMSS format, always in UTC time. In Perl (in which almost all my crons are coded) this is easy enough to break apart and turn into a UNIX time stamp. I then output the date in W3C ISO 8601 format as required by the schema. A sample of a resulting entry would be:
```
<url>
   <loc>http://www.gpf-comics.com/wiki/Nick</loc>
   <lastmod>2008-08-22T06:00:07Z</lastmod>
   <changefreq>monthly</changefreq>
   <priority>0.3</priority>
</url>
```
Change frequency and priority are purely guesses and fudges for mine. According to the sitemap specification, priorities are purely relative to other parts of the site. I rated the wiki pages as relatively low since the wiki at GPF is considered a “supporting” page and subordinate to things like the archive. As for change frequency, the sitemap specification includes a number of predefined choices (hourly, daily, weekly, monthly, etc.). Monthly was a purely off-the-cuff guess; some pages may update more or less frequently, but monthly would be a good average. It is entirely possible to rate select pages as higher priority or frequency than others, but I decided to take the easy route and rate everything the same. To apply different values, you just need to pay special attention to the title and assign a non-default value when that title crops up.

Well, I hope someone out there might find this helpful. I’m not sure if it really helps anyone find anything at GPF, but it was a fun little exercise nonetheless.
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WinHasher 1.3
June 30th, 2008 (1 month, 4 weeks ago) by Jeff | Permalink | Dump Core
For both of you out there who care, WinHasher has now been bumped to version 1.3. The changes are very minor, so there’s no need to upgrade unless you find the following two new features useful:
- There’s now a drop-down box to choose between hexadecimal output and Base64 (RFC 2045, although without line wrapping). I personally like using Base64 because it’s more compact than hex and more “obscure-looking”; even non-coders are familiar with hex, seeing it in error messages all the time, but are less familiar with Base64, which looks more like “random noise”. The default output is still hex, so you only need to switch modes if you really find Base64 more useful.
- There’s now a tab in the GUI to hash arbitrary text. I added this feature because there was an extension to Firefox that I used all the time to do this—which I used frequently to generate “random-looking” passwords by hashing simpler plain text and using the hash as the “real” password—but the extension hasn’t been updated in forever and is no longer working in Firefox 3. So to keep myself from getting locked out of the accounts where I used hashed passwords, I threw this feature in WinHasher. The backbone was already there, so all that needed to be added was a GUI. There’s also an encoding drop-down box that lets you change the text encoding if you so desire/need. To be honest, I don’t think it’s really necessary because I think .NET uses Unicode internally all the time, but it does have a nice side-effect: if you enter text in one encoding and change the encoding setting to something radically different (say you enter Western European Windows text but change the encoding to IBM EBCDIC Japanese), you’ll end up with a very different hash than you would have had if you used the “right” encoding. This isn’t encryption by any means as it could be easily reverse engineered if you knew what encodings were used, but it does significantly scramble things to the point that it makes it much harder to figure out exactly what you did.
I had originally started adding support for HMAC signed hashes but have abandoned that for now. If there’s anyone out there who might actually find that useful, drop me a line and I’ll revisit the code to see what I might be able to add. Downloads can be found at the first link above.
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Praise for XCache
March 18th, 2008 (5 months, 1 week ago) by Jeff | Permalink | Dump Core
The new GPF site has been running live for half a month now, and I’m proud to say things have been running incredibly smoothly. That is, at least, from my perspective; I haven’t seen any major glitches, and aside from a few typos in the comic (which are obviously independent of the site code), nobody has written me about any problems. This is especially heartening because the new site was pretty much entirely coded by hand by me, sans a few bits and pieces. (I can’t take credit for the OS, the web server software, the database engine, or the forum. But everything else… yep, that was me.)

There were a lot of motivations for writing my own archiving system, but the primary one was efficiency. While I considered trying something off-the-shelf, so to speak, like ComicPress or Drupal, I really wanted something that would be blazingly fast yet still dynamically generated to let me do things like GPF Premium on the server side, primarily for security reasons. (Server-side processing means no messy JavaScript is required by the users, thus exposing them to less risks, while Premium content doesn’t even get sent to the browser at all if Premium isn’t enabled.) So the GPF site is optimized out the wahzoo, with certain high-volume pages built once by nightly crons while others that require more interactivity reduce database queries to simple selects as much as possible. I’m never one to brag and toot my own horn, but I’m actually pretty proud of the new site and how responsive it is.

Of course, I can’t really take all the credit. I do have to give some serious props to XCache.

For those unfamiliar with PHP, it is one of many server-side, interpreted scripting languages commonly used for dynamic Web site development. The caveat, however, to any interpreted language is that on each request the source script must be read, parsed, compiled, and executed before anything is set back to the end user’s browser. This is one reason why dynamic sites are and will always be slower than serving purely static HTML files. Static HTML just needs to be read and regurgitated; anything that requires the Web server to actually think takes more time. Add to that the fact that there could be hundreds or even thousands of requests all competing at once for content and it’s a miracle anything get served at all.

XCache is one of several opcode caching extensions for PHP. Essentially, when the first request for a script is made, the script is parsed and compiled as usual. However, XCache stores the compiled code so subsequent requests can skip the parsing and compilation steps and go directly to executing the code. This significantly increases the speed of execution by eliminating one of the costliest parts of the process (except perhaps database connections). In addition, XCache also includes the ability to cache variables and objects, so commonly repeated and expensive variable generation–such as the cryptographic hashes I use for salting cookie hashes or database look-ups for common elements like the Premium subscription levels–can be stored in the cache rather rebuilt on each request.

I was first introduced to XCache by the XCache for WordPress plugin, which was probably mentioned in one of the development feeds built into the WordPress dashboard. I’ve been running this combination here on the blog for a little while with moderate success; I’m still trying to find a good balance of configuration settings to get the best results, but I’ve been happy with the results so far. Without putting much thought into it, I went ahead and installed XCache on the GPF server, hoping that it would help even if I never got a chance to optimize it. Fortunately, it has helped, and now that I’ve optimized the settings it’s exceeded most of my expectations. I’m not sure if there’s something about my code that caches better than WordPress, but GPF has done much better with XCache than the blog has.

Admittedly, I haven’t compared it to any other opcode cachers, nor have I benchmarked it against any of the competition. That said, however, I heartily recommend it to anybody running PHP applications. To get the greatest benefit, you may need to modify some code (or install a plugin if you’re using a prepackaged application) to take advantage of the variable/object caching. But even without modification the opcode caching alone makes for a vast improvement.
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Vista first impressions
December 10th, 2007 (8 months, 3 weeks ago) by Jeff | Permalink | 7 Core Dumps
I had my first brush with Microsoft Windows Vista this weekend. Like most hard-core geeks who are skeptical of just about anything Microsoft, I’ve read all the hype and negative press and have thus avoided it like the plague. I recently bought a new tablet PC (which just arrived today, woohoo!) and made sure to “downgrade” it to Windows XP. But this weekend as I was performing a Good Samaritan deed I was inadvertently forced to directly interact with Microsoft’s latest and “greatest” OS. And while there’s probably nothing new in this post to anyone who’s used Vista already, I’m sad to report most of what I’d heard and feared are true.

First, a little background. This past week, my sister-in-law’s notebook died. Exactly what happened is still uncertain; we know for certain that the video subsystem is on the fritz, which likely means that something is up with the motherboard (since the video is on-board). The LCD occasionally looks like a black light lava lamp, if that makes any sense, although I was surprised to have it actually work off and on with any given reboot. Windows XP crashes on boot on the NVIDIA video driver, which might (or might not) be consistent with a video hardware problem. Throw into the mix the fact that the system spontaneously reboots or locks up after a indeterminable period of time, sometimes as long as several hours or as short as ten minutes. I pulled out ever trick and tool in my geek arsenal and haven’t been able to completely diagnose the problem, let alone fix it. So now the task has become one of data recovery, and with a creative combination of a Knoppix “live” CD, a USB flash drive, and a USB external hard drive this has gone off without much of a hitch.

Now we introduce the new machine. Like its predecessor, it’s an HP Pavilion “media center” notebook. I put “media center” in quotes because while the old machine actually ran Windows XP Media Center Edition, the new machine runs Vista Home Premium. Other than the OS, it’s obvious both machines are built for one thing: to be a portable home theater system. Both have massive widescreen LCDs, dual huge hard drives, several gigs of RAM, and the latest processors for their time. Needless to say, both machines are meant to be powerful multimedia workhorses and they have the muscle to prove it. Thus, there’s no reason to expect the new machine to be sluggish or slow.

And yet, it occasionally was. HP, like many manufacturers, loads its new machines with tons of useless garbage software. That said, I was surprised to see how little junk was really pre-installed on this thing. So the only thing I can think of that was really bogging it down was Vista itself. I can’t be 100% certain of this as I didn’t take the time to really investigate (most of my time was spent extracting data from the old machine), but there were plenty of times Vista seemed to drag and stutter, sometimes becoming unresponsive for a few seconds.

The culprit, I expect, is the new “Aero” interface. Sure, it looks pretty. I’ll give it that. Compared to XP’s default Crayola-inspired interface (which is one of the first settings I turn off on a new XP machine), it looks slick and modern. But it also seems bulky and bloated. The moment I turned it off and went back to the Windows 95-ish “classic” interface the machine become much more responsive and easier to use. While it was cute watching windows “pop” into existence (something that will probably smell suspiciously like copyright infringement to any Mac OS X user) and the translucent window borders are a nice aesthetic trick, the performance cost is pretty high and not really worth it.

Then there’s the security model. I’d like to applaud Microsoft for finally taking security seriously and making a concerted effort to be responsible with its market dominance by forcing users to be more secure. But boy howdy, is it a bear to work with. Apple has been running attack ads against Vista in their “PC vs. Mac” campaign where the nerdy PC character has to ask permission from a Secret Service inspired man-in-black for every single thing he does. I thought that was funny at the time, but I didn’t really realize how true it was. Having now been trained and used to doing things as an administrator in XP, it’s a real shock to be stopped at every other mouse click with a warning that what I’m about to do has serious security implications. It’s not just a pop-up box, either; the entire screen flashes, dimming everything else and forcing to acknowledge the pop-up before you can continue. Yes, I’m aware of the serious security implications; I’m stepping outside the box and doing advanced things outside what a normal user is likely to do. (For example, moving the contents of the old machine’s “Application Data” and “Local Settings” folders, normally hidden, to their new home.) But do you have to warn me every single blasted time? Really. What’s worse is that this extends beyond some of the obscure, funky guru work I’m currently doing. Simple configuration changes are challenged with the same severity as drastic, devastating, and potentially damaging attacks. Where 95/98 was blatantly promiscuous (or more properly naive) and XP (post SP2) was cautious, Vista is downright paranoid. I half expect it to call in the FBI and the National Guard every time I change my wireless SSID.

Maybe there’s someone out there who can help. If you have experience with Vista and you know how to turn these security pop-up off, just for my login, at least until I’m done doing arcane geek magic to finish restoring this machine, please let me know. I think I’d be done in a fraction of the time if I didn’t have to babysit these prompts all the time. Even if it’s a setting that lets me check a box that says “don’t show this again” so I only get it once per action will be a big help.

After all that complaining, let me mention one thing I did like about Vista: parental controls. As a parent who is faced with a future where my young son will be a few clicks away from all the porn and identity theft of the Internet, I’ve been looking hard at third-party (as well as home grown) filtering and monitoring solutions. Vista apparently has this built in. Unfortunately, I have no idea how effective it is. My guess is that workarounds to bypass it are now just a Google search away. But still, just like XP’s firewall is more of an afterthought than a real security measure, it’s got to be better than nothing, and it will probably be easier to train my non-tech-savvy sister-in-law in how to use it than to explain about proxies and packet filtering. Depending on how long this machine is in my possession, I might try to experiment and see just how effective these parental controls really are.

Again, nothing necessarily new here that you probably haven’t seen everywhere else, but I thought I’d share my experiences to anyone interested in listening. I’m leaning more and more toward ditching Microsoft completely and going with a completely FLOSS setup, and Vista is helping push me in that direction. Then again, I had huge reservations about XP when it came out, too, so who knows what the future will bring?
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WinHasher 1.2
November 30th, 2007 (9 months ago) by Jeff | Permalink | Dump Core
I just can’t leave well enough alone. I’ve been mildly annoyed with the “hash in progress” and progress dialogs in WinHasher 1.1. The original idea was to use System.ComponentModel.BackgroundWorker to easily multi-thread very large hashes (say of CD or DVD ISOs or uncompressed video files). This had two benefits: (1) it allows the user to cancel a hash in progress and (2) gives us an opportunity to update the GUI while the hashing takes place in the background, meaning we can inform the user of the progress. Unfortunately, I couldn’t find a method right away to determine the progress of an individual hash. System.Security.Cryptography.HashAlgorithm.ComputeHash() by default takes a byte array or file stream and chugs the whole thing at once, spitting out the hash as a result. There’s no way with this method to determine how far along you are.

However, if you look at the guts of ComputeHash(), you’ll find it reads in chunks of bytes into a buffer, then calls two methods: TransformBlock() for every chunk but the last, and TransformFinalBlock() to hash the last chunk and finalize the hash. The result can then be obtained from the HashAlgorithm.Hash property. If we bypass the convenience of the single ComputeHash() method call, you can read chunks of bytes from the buffer, feed it to the Transform...() methods, and keep track of how many bytes have been read so far. Since we already know how big the file is from the start (System.IO.FileStream.Length), it’s trivial to calculate a percentage complete. Want the progress of a multi-file comparison? Sum the lengths of all files in the batch, then keep track of the total number of bytes hashed along the way.

I’ve bumped WinHasher to version 1.2. It should be available on the official site by tomorrow morning.
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WinHasher 1.1
November 9th, 2007 (9 months, 3 weeks ago) by Jeff | Permalink | Dump Core
I was downloading Fedora 8 yesterday with every intention of (eventually) upgrading Demeter, our Linux box, currently running Fedora Core 5. I say “eventually” because finding time to back everything up, install the new OS, restore all the files and third-party apps, and then spend hours debugging what went wrong is the hardest part of the whole process.

Anyhoo, I thought I’d put good ol’ WinHasher to use to verify the SHA-1 hash and make sure the download was successful. That was, after all, the primary reason I wrote the thing. But then I noticed something incredibly annoying. The DVD ISO for Fedora 8 weighs in at around 3.18GB. WinHasher has no problems hashing such a file as it hashes the file stream as it reads it, so it can hash any file of arbitrary size. But while it’s doing so, there’s absolutely no feedback to the user. In fact, if you use the right-click “Send To” shortcut, unless you go into the Windows Task Manager and check the process list, you won’t even know the thing is running. It seems to go off into la-la land until mysteriously, a minute or two later, it comes back with a mysterious pop-up box with a cryptographic hash in it.

Bad programmer! Bad!

Well, this annoyed me enough to fix it, so I’ve tweaked it now so it actually runs multi-threaded. This is ridiculously easy to do when you use the System.ComponentModel.BackgroundWorker object in .NET. You just create the object, create a few event handlers for it, and tell it to go do its thing. The hardest part is if you want it to report its progress; then you have to tweak your working code to generate a percentage complete so it has something to display. I learned this trick when I was working on Mandelbrot Madness! 2.0; I have no idea why it never occurred to me to incorporate it here. The annoying part about this addition, though, is that there’s no way to report on the progress of an individual hash. System.Security.Cryptography.HashAlgorithm doesn’t provide a way for you to know how far it’s gone, so there’s nothing to feed to BackgroundWorker.ReportProgress(). The comparison feature does, however, let you know how many of the files have been processed so far in the batch.

So if you’re one of the few brave souls who downloaded WinHasher 1.0, please grab 1.1 at the official site. It officially goes up tomorrow (a delay caused by Keenspot’s parsing to insert the advertising codes). If you haven’t already downloaded it, why not give it a try?
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WinHasher 1.0 and Mandelbrot Madness! 2.0
September 26th, 2007 (11 months ago) by Jeff | Permalink | Dump Core
I’m not sure if anyone cares, but I’ve been doing a tiny bit of dabbling in releasing Open Source software lately. Since I don’t particularly care to announce them on the GPF News (it isn’t, after all, GPF news), I’ll announce them here. For those of you who might complain that working on these has taken precious time away from the comic, fret not. The tiny bit of time I’ve been able to squeeze in here and there to work on these have been during periods when working on the comic would be impossible, so there’s no way for there to be any conflict.

The first one I’ll announce is the most recent. WinHasher is a Microsoft .NET Framework 2.0 application for generating cryptographic hashes of files. It is both a Windows GUI applet and a console (command line) program, and it operates in two possible modes. The first mode generates the hash of a single file, which you can then use to verify a download or check to see if a file has been tampered with. The second mode takes the hashes of multiple files and compares them; in this way, you can see if two or more files have the same binary contents regardless of their names, locations, and time stamps. The Windows app supports drag-and-drop functionality, and the installer lets you also build shortcuts in your Windows Explorer “Send To” context menu so you can just right-click a file and get its hash.

So why did I build this? Well, the full details are on the site, but the quick version is that I’ve grown tired of not being able to validate the hashes of downloaded files because Windows doesn’t have a built-in hashing program. Linux and the other free UNIX clones have OpenSSL; heck, even Mac OS has OpenSSL under the hood. Not Windows… of course. So instead of downloading a file on a Windows machine, copying it to the Linux box, validating the hash, and moving it back (or worse, just not even validating the hash at all and taking my chances), I hacked together this little program. Then I thought it might be useful enough to share, so I did. If you find it useful, please let me know.

For the really technically inclined out there, most of the hashes are built-in to .NET 2.0, so this was obscenely easy to implement. In fact, 2.0 has an abstract hash algorithm class (System.Security.Cryptography.HashAlgorithm) that all of the built-in hashes implement. The two non-standard hashes, Whirlpool and Tiger, were taken from the Legion of the Bouncy Castle Crypto API, which is actually .NET 1.1 based. I (rather crudely) ported these classes to be subclasses of HashAlgorithm, so they can technically be used as a drop-in replacement of any .NET 2.0 hash. I plan to add additional hashes over time, provided that (a) the original source code is free and (b) I can port it to be a HashAlgorithm subclass.

The second program to mention is actually a bit of an oldie now. (I actually released it back in June.) The Windows version of Mandelbrot Madness! is back, also in a .NET 2.0 edition. I wrote the original in Visual C++ 4.x, but have long since lost the source code. Then the Java version came into being and rapidly surpassed the Windows version, leaving it to suffer from bit rot. Both eventually languished as I lost time to work on them. Well, in December of 2005, I released the not-quite-complete-but-close-enough 4.0 version of Mandelbrot Madness JAVA!, declaring it abandoned. It always bugged me that I never went back and revisited the Visual C++ code, but without the source I was stuck.

Well, to make a long story short, my new job had me learning a new programming language: C#. That had me programing Web sites, but I knew you could also do Windows GUI apps in it as well. So somewhere down the line I got a wild hair and started the agonizing work of porting the Java code from the last version of MMJ! to C#. Actually, Java and C# are similar enough that the porting work wasn’t all that hard. Not only is MM! 2.0 now pretty much identical in functionality to MMJ! 4.0, but I introduced a number of new features that I hope to eventually port back to the Java version. While I still prefer the platform independence of Java, I’ll readily admit that the .NET version is a lot faster on Windows. I think that anyone on that platform that has actually bothered to play with the Java version (both of you) should make the switch. Anyone still using the decrepit old 1.0 version of Win32 MM! should enter the 21st century and upgrade too.

Both programs have been released under version 2 of the GPL (haven’t had time to really review version 3 yet), so the sources are also available. If you have any suggested changes, feel free to pass them along and I might incorporate them into the official builds (giving you credit, of course).
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Running “Dexter”
September 25th, 2007 (11 months, 1 week ago) by Jeff | Permalink | 1 Core Dump
Ordinarily, I don’t go about announcing underlying technology upgrades (for example, I just upgraded iptables and Apache this morning), but I thought this was mildly amusing and I thought I’d share. As the observant among you probably know, I’m running WordPress, which just released version 2.3, nicknamed “Dexter”. It is so named after the “great tenor saxophonist Dexter Gordon.” Darn… I was being hopeful….
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Move complete… I hope
July 11th, 2007 (1 year, 1 month ago) by Jeff | Permalink | 1 Core Dump
If you’re seeing this post, then welcome to the new server! Our new host is Slicehost, a small hosting service that caters specifically to online developers. I have to say that so far, I’m pretty impressed. I had a few bumpy points getting SSH started and the initial setup was so bare-bones I had to install a ton of packages just to get functional (including fundamentals like tar and which), but it’s moving a lot faster than the old site sitting behind the cable modem.

Slicehost does one thing that I think is really pretty slick, especially from a hard-core geek’s point of view: Unlike most web hosts who give you a little sandbox to play in and tie your hands on what you can and cannot do, the “slicers” give you your own virtual server with root access. That’s right, you have the keys to the virtual kingdom. That means you decide what gets installed on your box, from the Linux distro (no other OSes are supported at the moment, but they do offer several distros) to the individual server applications. Want a LAMP box? You got it. Prefer Fedora to Ubuntu? (Me! Me!) Here you go. You decide what gets installed. The caveat to such permissiveness, of course, is that if you screw it up, it’s your own darn fault. That’s okay, though, because your virtual server shouldn’t affect anyone else sharing the box and you can rebuild your “slice” at any time, wiping it clean and restoring it to its original pristine state. Pay a nominal extra fee and you’ve got backup snapshots that you can also restore in the case of catastrophic failure.

One thing to watch out for is the waiting list. They appear to allocate hardware dynamically based on their current user base (keeping some servers in reserve for redundancy) and then purchase new machines based on their projected demand. If you sign up for the smallest package with the minimum prepayment plan, you could be looking at several weeks of wait time. However, if you’re willing to pay a little more in advance, you’ll be moved up the list. I decided to prepay for six months instead of three and was told I’d have my “slice” in “less than a week.” I ended up getting it in a few hours. Yep, that’s technically less than a week.

Initial annoyances (I’m not sure I’d call them complaints):
- It appears something was up with their Fedora repository. My initial setup did not include the SSH package, and since that’s the only remote access package installed by default (telnet and FTP are rightly left in the bit bucket) , I couldn’t log on. I contacted their support site and got a response in about an hour or so. Unfortunately, it was already getting late, so I couldn’t stay up to see if the fix they gave would work. However, I was able to log in licketty split this morning with no problems. (I then took the opportunity to lock the box down tight; this site proved quite helpful in that regard.) A small part of me cringes inside, wondering what might happen if I have to rebuild my slice and this repository isn’t working again….
- While it’s great that they give you a clean slate to work with, they really give you a clean slate. As mentioned above, some things you just take for granted on a *NIX box like tar and gzip were nowhere to be found. I think it’s fine that I have to install MySQL, Apache, and PHP on my own; not everybody’s going to use those and they may have a database, Web server, or scripting environment they prefer over those options. But no tar? No gzip? Not even which? I lost track of how many seemingly fundamental packages I had to install, stuff I just naturally expected to be there. Not a major complaint, mind you, but an annoyance, as it took far longer to get the system to the point that I could actually function than it did to get the blog moved.
All in all, though, I think I’m going to like this new home. If you’re interested in checking them out, click the link in the first paragraph and poke around. If you decide to sign up, though, come back here and click my referral link. A little kickback is always nice.

Of course, now that we’ve moved, commenting should be re-enabled. If you created an account before the move, it should have been ported over. (The internal user ID numbers got switched around, but since no one was able to post after I switched to WordPress, I don’t think that really matters.) Feel free to log in and make sure your account is accessible.

Feed readers: Please update your feed links now. You’ll find the new RSS and Atom links in the “Feed Me” section of the sidebar. Remember, the old “domain:port” URLs will no longer work.
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Software, Technology
Sometimes it makes me feel dirty…
November 13th, 2006 (1 year, 9 months ago) by Jeff | Permalink | 1 Core Dump
Been meaning to blog about this for a while, but I just haven’t gotten around to it. I mentioned my new job a while back and gave you updates about the resulting move throughout that process, but I never really mentioned much about the job itself.

I work (as a contractor) for a company called ManTech. I’m currently working on a number of projects, all of which either directly interface with or are satellites of our main project, which consists of computer based training for the Navy Reserve. We’ve used a standard called SCORM to develop a Web-based learning management system. We then take a series of computerized training courses–some developed by a partner company and converted by us to a Web format, and some developed in-house–and provide the necessary back-end to maintain the learner’s training history and progress. My first project was actually to build a content management system to manage photographs and other content that support our artists while they generate graphics for these lessons. I’ve now moved more deeply into some of the other projects directly interfacing with the LMS, and I’ve been tapped to become our resident expert on CORDRA.

The real meat of where I’m going with this, however, is that I’ve had to learn a whole new programming language. I’ve worked with a number of languages over the years, most notably Perl, Java, and SQL. The complete list is actually quite lengthy, but many languages I “know” (like C/C++) I haven’t touched since college or I’ve taught myself to use for my personal amusement and have little to no professional experience with. Perl fit into the latter category until my last contract assignment; technically, so does Java, as I’ve mostly used it for personal projects. (I did do some Java work on the early GPF site though, but mostly behind the scenes.) Unfortunately, a good chunk of my professional work since college was tied up in report writing using technologies such as BusinessObjects and FOCUS, a realm of the IT industry I’m thankfully starting to escape from. (I graduated from college expecting to program, not build reports with pre-packaged tools.)

When I applied for this job, I knew they were looking for someone with Java (or some other object-oriented programming) experience. What surprised me was that while they seemed to be looking specifically for someone with a little Java know-how, the real language they were planning to use was C# .NET.

Now anyone who has followed GPF long enough should know by now that I’m not a big fan of Microsoft. Yes, I use their products (one almost has to if they want to function in the computer world), but their history and business practices speak volumes about their corporate ethics. I’ve dabbled a little in Windows programming over the years; I’ve toyed a little with Visual Basic and took a course in Visual C++ back in college but never did much with that beyond a little playing with fractals. In general, though, I prefer to focus on technologies with strong cross-platform capabilities, mostly because I feel that users should not be discriminated against due to their personal choice or corporate mandate of operating system. This, among many other factors, often makes me lean toward open source.

The Reserve, however, like many government and corporate technology departments has mandated a “standard” platform for use within their organization. This platform, as you might guess, is largely based on Microsoft technologies. Thus, almost all of ManTech’s development work (at least on this family of projects) is done in Visual Studio 2005. Many of our projects are Web-based, so we do a lot of ASP .NET work with C# as the chosen language. (.NET uses a common language infrastructure so it doesn’t matter what language you actually use to build your application in. It all compiles to the same bytecode, which the runtime then executes.)

Now I had heard a lot of comparisons between Microsoft’s .NET and Sun’s Java platform; indeed, a Google search turns up a ton of them (over four million results at this writing). I remember when Microsoft first announced .NET, and recall the buzz that it would destroy Java much like how Internet Explorer decimated Netscape in the browser wars of the 1990s. (Personally, I don’t see that happening, especially since .NET is only available on Windows, but projects like Mono could help bring .NET to other platforms while biting into markets that Java currently has dominion over.) So I was quite curious to see what .NET could do, and whether or not I might find myself on the other side of the fence once this was all over.

Well, I’m not over–or even on–the fence, but I’ve learned to appreciate the various tints of green on either side. My previous experience with Java made jumping into C# and .NET relatively easy, and I found myself writing real, useful code quicker than I expected. There are even some things that are much easier to do in C# that they are in Java, like designing the GUI. (This, though, is more a function of the IDE than the language, and is one place where Microsoft has always shined. Visual Studio can sure make a programmer lazy, which isn’t necessarily a bad thing. Then again, I’m also trying out Eclipse for Java work, so that might swing that factor into balance.)

My experiences with C# these past few months haven’t killed off my interest in Java, but it did prompt me to download Visual C# Express to do some off-the-clock experimentation. It even reinvigorated one of my old side projects; there’s a chance that Mandelbrot Madness! may get a new .NET 2.0 Windows version that is roughly comparable to the much more up-to-date Java version. I’m curious to see where .NET is going to eventually end up. If I can keep up with it, I’ll try and post more thoughts on these technologies when I can.
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