I've been looking at Azure Traffic Manager lately and I've had a demo environment set up for a few weeks now. This was both for my own personal development and also in preparation for a demo/presentation that was I was delivering.
If you'd like to see that presentation in full here it is:
I noticed earlier today when I was looking to dig into some of the features and create some videos around them that my Monitor Status was showing as degraded, which was strange!
Azure Traffic Manager has endpoint probes that are used to ultimately determine if they are there and healthy and ready to receive traffic. Ultimately trying to avoid routing your end users to an endpoint that isn't available.
How do probes work
Before I tell you what I did to fix this situation, let look at how Traffic Manager probes actually work and think.
- A probe will consider a endpoint online if it gets an HTTP 200 response back from the probe path.
- For HTTPS probes any certificate errors are ignored.
- A 30X redirect response is treated as a failure unless you've specified that as a valid response.
- If all endpoints are reporting as DEGRADED then Traffic Manager treats all endpoints as healthy and routes traffic to the endpoints.
All my endpoints were reporting as degraded meaning traffic was getting routed. After a few minutes of scratching my head, I was unsure what had happened. And then the penny dropped!!
I had set my endpoints/web apps up to ONLY use HTTPS and my probes were set to look for HTTP. Meaning the tests were failing.
As I wanted to changed all my endpoint probes to HTTPS tests, the easiest and quickest way for me to do that was to go into the "Configuration" blade within my Traffic Manager and change the Endpoint Monitoring Settings to HTTPS.
Saving this new configuration and waiting a few moments resulted in my Traffic Manager endpoint monitoring status to return to online. 😊
Definitely a lesson to me that one change somewhere can have a negative impact elsewhere! Hope this article helps you understand a bit more about Azure Traffic Manager endpoint monitoring.