This is a pretty simple problem, but when I was searching around for it, I didn’t see any reference to my particular resolution, so this is mainly to help in case anyone else experiences the same problem.
I recently had a problem with Magento in which it seemed in the Cart and during the onepage checkout, the area showing the subtotals and the grand total had suddenly gone missing. After more hunting around than I care to admit, I ruled out a problem with the store’s theme, since another store set to the same theme had no such problem. Most configuration options were also identical, which ruled them out as the cause as well.
So, assuming it was a configuration problem, I started going through and comparing. In the problematic store, several modules are disabled, so I started turning them back on, just to rule out that as a possibility. The working store had everything still at the site defaults. It turns out that the problem was simply that Mage_Tax had been disabled. Re-enabling it immediately made the subtotal and grand total reappear. To me, at least, this doesn’t seem very obvious or intuitive, but that’s what it was.
Someone, anyone – please improve the PerlMonks website.
It’s such an invaluable resource, with with major names in the Perl community like chromatic and Randal Schwartz and brian d foy. It’s one of the best places to go to just read about in-depth Perl questions people have, to see what other people are doing with Perl, and to generally learn about Perl.
The site, in terms of content and community, is incredible. The site, in terms of the software itself, is deplorable.
It’s not just hideous, it’s built on old, bad design. It wasn’t long ago they even had plaintext passwords leaked. Plain text passwords. On one of the most important sites for one of the biggest languages on the web. If that isn’t indicative of the problem alone, I don’t know what is.
Perl is a great language, it deserves better.
Sometimes I forget how useful the little-used parts of CSS can be. I happened to see a quick screencast about the usage of CSS Counters in my RSS reader today though, and immediately was surprised I hadn’t seen this more often. It’s definitely something I’ll be keeping in the back of my mind.
My first thought while watching, in case someone gets the same idea, is that he’s just making a list. If he wants to number them… use an ordered list. The problem is that he’s using an overly simple example – you could also use these counters in a more complex chunk of HTML. For example, suppose each comment on a blog is in a <div>, with many parts of the comment (author, date, etc) in spans and divs within it. You could take an arbitrary span or whatever tag you like and assign the numbering there, rather than the more limited options an <ol> gives you. It might be possible to still do something like that with an <ol>, but while I’m far from a CSS expert, I don’t see how, and I especially don’t see how it would be as elegant, if it can be done.
For those who aren’t already aware, the Wayne State University Linux Users Group (henceforth referred to as WSULUG because the full name is quite a long one) has been ramping up a bit lately, with activity on the mailing list and ideas being kicked around for meetings, presentations, and so on.
We’ll also be at Student Organizations Day, September 14, on Gullen Mall. Feel free to come stop by between 11am and 2pm and meet some of us, find out what we’re doing, get a Linux installer (we’re planning on having some Ubuntu installers burned to CDs there), and so on. The people in our group run the range of new Linux users to enthusiastic system administrators, so don’t be intimidated if you’re just curious to learn more, or haven’t even ever seen Linux before. A LUG is one of the best ways to get started.
I recently ran into a problem with a site I wrote in CodeIgniter, and I didn’t see much that mentioned it, so I thought I’d post about it in the hopes that if it came up for someone else, maybe I could be of some assistance.
When developing the site locally, everything was fine. On a testing server, it was fine at first, but as more people started testing on it, we found that now and then, the site would simply stop responding. The browser would just stay at the “waiting for server xyz.edu”, apparently indefinitely. We have our subversion server set up to automatically deploy the HEAD tag to the test server, and there’s a web interface to manually deploy a given revision (defaulting to HEAD) whenever. The odd thing was that this hanging problem seemed to be cured (usually, but now always) by pushing the current version out to the server. Sometimes it only cured it for a few seconds or minutes, but often, it seemed fine for hours or days. As time when on, though, it came up more and more often. Oddly, it was only with this site that the problem showed itself. While the site as unresponsive, other sites on the same server seemed fine.
At first we thought the server was just getting bogged down with some process that was using up CPU cycles, or network connections, something like that. Watching htop for a while did show a coworker’s python script coming up, but even that didn’t seem nearly severe enough to be the cause. We also had a bit of trouble with the database server while this was going on, so that was also suspect, though I would be able to connect while the site was unresponsive, so that didn’t seem likely either.
With some help from a coworker, we eventually did come up with the cause, at least in part. We did a list of all files in the site’s directory before the problem happened, and then refreshed the site rapidly using a highly technical method (we hit F5 and held it down until the site died. Then we redeployed from svn, and did another file list, then diff’ed the two. The only difference was CodeIgniter’s own log file that it generates in system/logs by default. After the deployment, the log was cleared. We also noticed that while the site was unresponsive, the log directory had what appeared to be a temporary dot file left by NFS. There was our clue – the directory that hosted sites were stored was in fact an NFS mount.
I’m familiar in brief with what NFS is and what it’s for, and so on, but by no means am I an expert or even a frequent user. It appeared that in this case, though, that maybe the mount wasn’t expected for so much writing as a web log (a fairly heavily verbose one at that, as we we still actively developing the site). It makes sense to me at least – typically you don’t log there, you log in /var/log or something, and the site itself is just a bunch of files you only read from. I wouldn’t be surprised at all if the NFS mount was, or was configured to be, set up for a lot of reads and very few writes, and when the site hammered it with file writes, it slowed to a crawl, as it turned out that if you tailed the log while it was unresponsive, lines were still written to the log, just very slowly. As in, several seconds in between lines indicating nothing more than a PHP class being instantiated.
So, regardless of the gritty technical details of the problem that I haven’t had time to investigate yet, the problem was then easily solved – I just turned off logging altogether, and the problem hasn’t surfaced since.
The lesson learned, for me at least, is to be mindful or where you’re writing.
This came from a survey from a magazine that, judging from the content of the rest of the survey, is considering or planning on offering a digital edition. I’m a little amused that they did decently on including the major browsers (I wouldn’t think much of it if they hadn’t included Opera, for example), but somehow thought “Linux Kernel” was another browser.
I did check it, though. I mean, technically I’m using the Linux kernel to post this right now, there’s just a few layers in there somewhere.
While glancing at vim plugins today, I came across one that’s really nice so far: EasyMotion. The page there has an animated image showing what it does in a nutshell – you hit \w, and it gives you a letter of the alphabet for each possible word, then you hit whichever you want to go to. Small thing, but it makes moving around in the file much quicker, and code editing that much more fluid.
Just thought I’d share in case there’s any other vim users around here.
While it’s something I’ve kind of wished for since coming back to Wayne State, a recent conversation with a coworker (and a recent blog post by Geoff Nathan) reminded me of my slight annoyance at the lack of widespread support of email encryption and signing. A quick search for gpg support in Zimbra doesn’t really turn up much, and in fact it lead to me find that a Firefox plug-in I once experimented with using, FireGPG, is now discontinued, and that was my first idea for a somewhat hackish way to do it.
There is, of course always the option of just abandoning the Zimbra web interface and using Thunderbird, KMail, Evolution, or any number of other desktop clients with gpg, but that has the downside of giving up some of the nicer features of the interface, as well as parts of it that I use that aren’t going to be in those desktop clients. There’s also the downside that it would drastically impair my ability to read email on a mobile device, but that’s true even if Zimbra did have good support for encryption.
As it is now, the best way I can think of so far (and admittedly, I’m still thinking about it now, so I may come up with something else better) is to just use a desktop client for more “secure” correspondence, and whatever other clients for “everything else”, when I’m away from my desk. Realistically, while I’d love for as much of my email to be done in a secure way as possible, most people don’t have a public key out there that I could use anyway, so 99% of my email would be the same as it is now. The only time I’d have to start up a desktop client would be on the rare occasion a more enlightened coworker sent me something encrypted, or if I wanted to confirm their signature. Alternatively, I could just use the desktop client full-time, and start up the web interface for those few things that desktop clients can’t do. CPU cycles are cheap anyway.
I’ll have to dig around more, but I think this touches into a bigger problem of so many things being insecure. I shudder to think how many times my social security number has been emailed around in plaintext documents at old employers or the like, to sit around on someone’s email inbox protected by someone’s password that’s no stronger than their dog’s name.
I graduated from Wayne State in 2008, and started working at a job remotely. Very shortly after I graduated and suddenly had little driving to do anymore, gas prices fell from their then-record high of around $3.5-4/gallon (IIRC) back to more normal levels. “It figures”, I thought.
Go forward to today. I came back to WSU as an employee in January 2011. A couple months later, gas prices approach record levels in Michigan again, now that I’m back to having a daily commute.
The conclusion is obvious. The more driving I have to do, the more expensive gas gets. It’s all my fault. I’m sorry, everyone.