Last week DasBlog freaked out on my blog and pegged the CPU on my Windows Azure Web Sites (WAWS) hosted blog. Because I had it configured as a Shared instance (which allows me to point my custom briannoyes.net and briannoyes.com domains at it from DNS), there are Usage Quotas that kicked in for how much CPU time your site can consume in a given window and my site got suspended for exceeding those quotas. As a result, my blog was down for almost a 24 hour period until the quota gets reset.
When I discovered the problem (thanks to @MLaritz for alerting me via Twitter), I thought “well, I can just scale it up to a Reserved instance for a period until the quota gets reset and then can scale back down.”
What surprised me was when I tried to do that I got the following warning:
"This will upgrade all web sites in the West US region to Reserved mode. This will take several minutes to complete and your sites will keep running during the process."
I had two other sites on the same account in the same sub-region, and this made it sound like they were each going to become a Reserved instances (billing out at ~$57/mo instead of ~$10/mo for shared). So I instead opted for waiting and letting my blog be down for a day.
I followed up with the Azure team and was pointed to this great post by Brent Stineman. The important subtlety here is that yes, in fact all of my sites would have been moved to a Reserved instance, but they would all be moved to a single instance and it would basically become a dedicated VM acting as a shared host for all of my sites, which I could then scale as appropriate. That means if you have more than 6 sites you would actually save money compared to the shared hosting option. Well, in my case I only had three and it would have been a little more expensive, but no where near what I thought it was telling me – that I would jump to paying 6 X 3 = 18 times as much.
So just realize that when you scale from Shared to Reserved mode and you get this notice, it means those sites will be moved together to a single reserved instance, not individual instances.