Nginx + WordPress + Infinite Redirects

As I was migrating my websites to a new host (I may blog about that later as it’s been an interesting ride), I had this lovely issue where one of my websites would go into an infinite redirect loop when sitting behind the Azure CDN (custom origin).

Of course, it worked fine for all pages except for the root.  And it also worked fine when it wasn’t behind the Azure CDN.  For whatever reason, adding a bit of code to the functions.php theme seemed to work.

remove_filter('template_redirect', 'redirect_canonical');

I then had to add in a manual redirect in nginx via the below.  Still no idea why it doesn’t just “work” as it has before, but whatever. Now that it’s working, I should go back and figure out why it wasn’t with redirect_canonical…

server {
   listen 80;
   rewrite ^ $scheme://$request_uri? permanent;

SQL AlwaysOn Avail Group Failover and Client Disconnects

We had an issue recently where an application was not properly getting disconnected from SQL during a failover of an AlwaysOn Availability Group (AOAG).  Some background:  The application was accessing the primary node, and after the failover the application continued to access the same node.  Unfortunately, as it was now read-only, the app was not very happy.

Turns out it was due to the Read-Only configuration of the secondary.  We had it set to “Yes” which allows any connections to continue to access the secondary with the assumption the application is smart enough to know it can only read.  It appears while using this setting, connections aren’t forcefully closed, causing all sorts of issue.

Setting it to either “No” or “Read-Intent Only” properly severed the connections for us.  Yay!

For more info.

Ubuntu and Heartbleed

One of the challenges with running my own server now, is making sure everything is properly patched.  With the big stink around the new Heartbleed vulnerability, it made me look into it a bit.

Turns out, in order to fix you can run the following:

sudo apt-get update
sudo apt-get install -y libssl1.0.0 openssl

# Confirm Build Date is at least Aril 7th 2014
openssl version -a

# Restart all services listed by this command:
sudo lsof -n | grep ssl | grep DEL