1. Azure Service Level Agreements (SLAs)
Agreement within Azure or SLA. A service level agreement in business in general is basically the service provider making certain commitments to the service consumer. And maybe there are either financial or other penalties associated with not meeting those commitments. When it comes to Microsoft Azure, for almost all of Azure services, Microsoft does make you some promises in the form of service level agreements. And if they don’t perform those promises, then you are entitled to a partial refund. So you can find that under the Azure Microsoft. com site support legal SLA. And I often find it’s good to use your search engine and search for Azure Virtual Machine SLA. And that will take you to the specific SLA that you’re interested in as well.
If you do go to this website, you’ll be able to find the various products that Microsoft offers and you’ll find out what the particular promise is that they’re making and what the consequences are if they don’t keep that promise. So here is an example of a service level agreement for Azure Virtual Machines. You can see that it was updated in the middle of 2020. Now there are five separate promises being made as summarized here at the top. I’m not going to go through each and every one of them, but it’s just good to understand that there’s a part of it where you have an obligation. So you’re going to create two or more virtual machines across two or more availability zones in the same region. That’s your obligation. And then Microsoft’s obligation is they will guarantee virtual machine connectivity to the Internet of at least one instance for 99. 9% of the time. There are obviously four other promises for availability sets and three promises for single virtual machines. And you can see there’s slight differences in the percentage being promised from 99. 9 to 99. 95 and 95. Now that’s the promise. Now what happens if they don’t meet their promise? Okay, if we go under SLA details, we can see that they’re promising a service credit for this particular one. The two or more availability zones of 10%, 25% or 100% refund on the cost of the services. So if they don’t meet this guarantee, then you can apply for a refund.
There are obviously different uptime guarantees depending on availability sets or for single virtual machines, has different guarantees and different refunds. Now each service is going to be slightly different. Okay? So if that’s the virtual machine, it’s pretty straightforward. If we choose something like, let’s say, load balancer, you will see that the promise is quite straightforward, right? The standard load balancer has a 99. 9% SLA. The basic load balancer, which is the free one, does not have an SLA. So every service has a different promise obligation on your part, a promise on Microsoft’s part, and a refund level if they don’t meet their promise. So that is the basics of an SLA in Azure.
2. Azure Service Lifecycle
Now we’ve said a couple of times that preview features themselves are not generally tested on certification exams, with some exceptions. But the reason is because they can change at any time. Microsoft can modify a preview feature or even just remove it. They decide that the thing that they were testing wasn’t worth it. They don’t actually recommend that you use a preview feature in production use. So they’re going to release is a preview feature and they want you to play with it, develop with it, give them feedback. But if you start putting it into your production environment, bad consequences can happen.
So for instance, there’s no SLA and it could obviously change. They could just break the API, or they can just decide to not make the feature go live. And I’ve seen that happen. There are two types of preview features. One is called a public preview and one is called a private preview. Now, typically we see public previews, but from time to time there is a private preview. So public preview is just a feature that is marked as preview. And you can just use it, right?
So we saw with the Azure Blueprints feature earlier in this course, it was marked as preview, but we could still just go in and create a Blueprint. There was no application process to do that. The private preview process, sometimes you will see it being a form to fill out. They are looking for people who are operating in a certain area, and so they want to vet those people first. So it might be like an AI feature and they want to work with people who are in that AI space. And so they ask you to fill out a form and then they grant you access, and then they can monitor your access. Or you can fill out a survey or something like that.
So we can see here they announced these things on the blog. There’s a couple of places where they announce them, but you can see it says announcing a private preview of this particular service. And so it’s definitely something available to you. But you do have to fill out an application and then they’ll either preview or not. Now, besides the two preview options, the most common is called General Availability or Ga. So obviously the majority of Azure features are in Ga. And then when something does get approved and proceeds from the preview state, they get into Ga. And you can see an announcement like this saying that this feature is now in Ga.
