uWSGI and Database Lockups with SQLAlchemy

If you’re running a Python-based web application and using SQLAlchemy as your database integration layer (as an ORM or otherwise), you may also be using uWSGI to act as the application container.

If you try and fire up multiple processes to handle greater load coming in with the uWSGI option --processes (or -p, --workers; or uWSGI’s various configuration mechanisms), then you’ll probably find that after a short time, your web application will lock up and refuse to serve requests. For me, this was between 1 and 10 requests with using the cx_Oracle database adapter against an Oracle …

in Web · Mon 26 August 2013

Unlocking your Telstra Elite (ZTE MF60) Mobile Wi-fi Device for Free

Ha, that’s a dodgy-sounding title if I ever heard one. If you’re reading this, then I’ll assure you that these instructions are real, open, and free, and that I’ve used them to unlock my device. Read on…

Update: I should mention that hexecute’s site at https://sites.google.com/site/mf60guide/ now mentions his patch can unlock as well. I haven’t tried that, but from memory, the Windows drivers that are available on that site didn’t work with my MF60 - presumably a different model or something similar. If what’s there doesn’t …

in Freebies · Tue 30 July 2013

All Fanstatic resources being served with ‘text/html’ mimetype by WebOb/WSGI

If you’re finding that you’re using Fanstatic to serve static resources within your Python-based server process, you may be left scracthing your head if you suddenly find that resources aren’t being served correctly. For me, this was manifesting as an incorrect Content-Type header, always being set to text/html for any type of static file being served. As a side effect, because I’m using Diazo to theme my backend Pyramid application, this was automatically seeing this mimetype being returned to the browser and trying to “theme” the raw files. The global picture looked like a whole …

in Web · Mon 29 July 2013

Attributes not released to new Shibboleth Service Provider (SP)

Just created a new Shibboleth Service Provider (SP) instance and found an Identity Providers (IdPs) is not releasing attributes to you? Don’t worry, you’re not alone. In fact, the issue is far more common than you think, despite a lack of documentation on the web.

in Web · Tue 28 May 2013

uWSGI and libxml2 conflicts (aka Installing uWSGI with a custom libxml2)

If you’re using uWSGI with XML support (this is its default), then it will be requiring you to have libxml2 installed — or something similar that provides xml-config. What you’ll find is some erratic behaviour (or complete failure) when attempting to serve an application that is also relying on libxml2, but a different version.

In my case, my original uWSGI was built with CentOS 5’s stock libxml2 library, but my Python application was using lxml, built with a custom version of libxml2 (via Buildout with the z3c.recipe.staticlxml recipe, in case you were curious). Because of these …

in Web · Wed 08 May 2013

Integrating Nginx and a Shibboleth SP with FastCGI

in Web · Mon 22 April 2013

Setting up a Shibboleth SP with FastCGI support

Good news! The Shibboleth SP software features FastCGI authorizer and responder applications for use with your favourite non-Apache and non-IIS web server. Unfortunately, the default distributions don’t come with it built by default. I’m looking into why this is the case, but for now here’s how to rebuild the RPMs yourself.

Note: if you’re just looking to download something that works and don’t want to rebuild things yourself, we have RHEL 6, x86_64 packages available in a Yum repo at https://www.hpc.jcu.edu.au/rpm/. You’ll also need to trust my …

in Web · Mon 22 April 2013

Shibboleth SP logo.jpg missing from distributions

Have you recently installed the Shibboleth SP software and found that the error pages the software is generating are missing the Shibboleth logo? If so, it’s because those error pages are attempting to display a logo (typically /shibboleth-sp/logo.jpg by default) but the logo of the Griffin that you may have been used to seeing is no longer distributed with the software.

Unfortunately, this change doesn’t appear to be documented (yet), but is highlighted in this discussion: http://shibboleth.1660669.n2.nabble.com/Shibboleth-logo-in-Red-Hat-RPM-tp7583386.html

More or less, the reasoning given is that the Shibboleth …

in IT · Mon 22 April 2013

Switching to Nginx from Cherokee: Techincal Guide

This is a follow up to a previous post on Switching to Nginx from Cherokee. Read that in case you’re here and haven’t already.

All information here on a server level is related to RHEL 6. You will need to change some instructions for Debian based systems. CentOS should be fine and needs only a minor URL change in the repo configuration.

1. Edit /etc/yum.repos.d/nginx.repo and add this:

   [nginx]
   name=nginx repo
   baseurl=http://nginx.org/packages/rhel/$releasever/$basearch/
   gpgcheck=0
   enabled=1
   

2. Run yum install nginx to install Nginx.

3. Start rebuilding your …

in Web · Fri 12 April 2013

Switching to Nginx from Cherokee: Why

After a switching away from Apache some time ago, our primary web server had been running Cherokee for quite a while - since September 2011, in fact, looking back at the configuration history. More recently, however, I’ve switched us again. This time to Nginx - with impressive improvements in performance and configurability (10x for some static files) — and reliability.

in Web · Thu 11 April 2013