Skip to main content

Great Example of How Our Users Help @mach_ii

My former co-worker Brandon Culpepper (who is still one of the quickest studies I've ever had the pleasure working with) ran into a bit of a bizarre issue with Mach-II yesterday, and after hearing him describe it I was determined to get to the bottom of it.

The gist of the problem was that for some reason after a session timeout occurred, the application would throw a rather non-descript error along the lines of "Element {directory name} is undefined in a Java object of type class coldfusion.runtime.ApplicationScope," and a slightly different error in OpenBD. You can read the full details in the ticket.

Brandon described the issue to me in great detail over IM, but it was one of those things I had to run locally to really get my head around it, and he was nice enough to take the time to not only whittle the problem down to a very specific, repeatable test case, but he sent me two different test applications that had only the elements we needed to be able to repeat the error and figure out what was going on. This was no small amount of work on Brandon's part and was tremendously helpful in getting to the bottom of the issue.

Using these sample apps I was able to figure out that it didn't throw the error if the hyperlink or AJAX call involved was a Mach-II event as opposed to a plain old URL, and at that point I submitted the ticket because I knew Peter, as lead developer of Mach-II, would be able to diagnose things much more easily than I could.

So Peter jumped on the case and figured it out rather quickly. It turns out that this is a rather weird bug that goes back probably to Mach-II 1.1.1 and has to do with the way Mach-II has auto-generated the MACHII_APP_KEY property based on directory names. If you hit a .cfm file or remotely call a CFC in another directory, that will trigger a change in the app key property, and since the app key property changes, Mach-II will think it hasn't been loaded. Note that this only occurs if you don't explicitly set the application key (which I always do), and only reared its head with the introduction of the onSessionStart/End methods in the Application.cfc boostrapper.

Peter came up with a fix that's currently being tested, and he makes note of it in the ticket, but I'll test posterous's code handling and stick it here:

<cfparam name="MACHII_APP_KEY" type="string" default="#GetFileFromPath(ExpandPath('.'))#" />

Note that you can also explicitly set the MACHII_APP_KEY variable to your application name as opposed to relying on the directory name and this will also fix the problem:

<cfset MACHII_APP_KEY = "whatever" />

So I wanted to take a moment to thank Brandon for notifying us of the bug and doing quite a bit of work to help us come to a quick rationale behind and resolution for the bug. Without the diagnosis and sample apps from Brandon this would have taken a lot longer to figure out, and due to his work all Mach-II users will benefit from Peter's fix to a bug that would likely bite others from time to time.

Another great open source success story. Thanks again Brandon!

Comments

Peter J. Farrell said…
FYI, the real fix is:<cfparam type="string" />The fix listed is the old code (sorry, if I messed on the code on the ticket).

Popular posts from this blog

Running a Django Application on Windows Server 2012 with IIS

This is a first for me since under normal circumstances we run all our Django applications on Linux with Nginx, but we're in the process of developing an application for another department and due to the requirements around this project, we'll be handing the code off to them to deploy. They don't have any experience with Linux or web servers other than IIS, so I recently took up the challenge of figuring out how to run Django applications on Windows Server 2012 with IIS.

Based on the dated or complete lack of information around this I'm assuming it's not something that's very common in the wild, so I thought I'd share what I came up with in case others need to do this.


This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Assumptions and CaveatsThe operating system is Windows Server 2012 R2, 64-bit. If another variant of the operating system is being used, these instructions may not work properly.All of the soft…

Installing and Configuring NextPVR as a Replacement for Windows Media Center

If you follow me on Google+ you'll know I had a recent rant about Windows Media Center, which after running fine for about a year suddenly decided as of January 29 it was done downloading the program guide and by extension was therefore done recording any TV shows.

I'll spare you more ranting and simply say that none of the suggestions I got (which I appreciate!) worked, and rather than spending more time figuring out why, I decided to try something different.

NextPVR is an awesome free (as in beer, not as in freedom unfortunately ...) PVR application for Windows that with a little bit of tweaking handily replaced Windows Media Center. It can even download guide data, which is apparently something WMC no longer feels like doing.

Background I wound up going down this road in a rather circuitous way. My initial goal for the weekend project was to get Raspbmc running on one of my Raspberry Pis. The latest version of XBMC has PVR functionality so I was anxious to try that out as a …

Fixing DPI Scaling Issues in Skype for Business on Windows 10

My setup for my day job these days is a Surface Pro 4 and either an LG 34UC87M-B or a Dell P2715Q monitor, depending on where I'm working. This is a fantastic setup, but some applications have trouble dealing with the high pixel density and don't scale appropriately.
One case in point is Skype for Business. For some reason it scales correctly as I move between the Surface screen and the external monitor when I use the Dell, but on the LG monitor Skype is either massive on the external monitor, or tiny on the Surface screen.
After a big of digging around I came across a solution that worked for me, which is to change a setting in Skype's manifest file (who knew there was one?). On my machine the file is here: C:\Program Files\Microsoft Office\Office16\LYNC.EXE.MANIFEST
And the setting in question is this:
<dpiAware>True/PM</dpiAware>
Which I changed to this: <dpiAware>False/PM</dpiAware>
Note that you'll probably have to edit the file as administr…