What are the disadvantages of canary deployment?

What is the alternative to canary deployment?

I've always thought that the canary deployment is an alternative to traditional roll-out for your product.

But how does it compare to a traditional rollout? This is my personal view of how canary deployment compares to roll out: Rolling out new features: When rolling out a new feature you need to test whether the feature will work correctly and is usable. Testing all possible scenarios is important when you are rolling out new features. You want to test: Your feature does work correctly. Your feature does not break anything that you have already deployed. Your feature does not break anything that you are currently working on. The canary deployment model is based on this principle. Testing new features for completeness and usability without having to change anything else is the biggest benefit. To do this you can use the canary deployment model. Your canary deployment model: There is a single user (canary) with an isolated instance of your application. This canary user can be used to: Create a snapshot of your application state when there is nothing wrong. Run your new feature without any interaction with your existing system. Testing new features: When you want to deploy your new feature, you can push it to the canary user's instance of your application. If the canary user is already running your application you can upgrade the canary user's instance of your application by pushing the new version to it. If you already have a deployed version of your application, you can roll out the new version to all of your users by pushing the new version to all instances of your application. Canary deployment: You only update your application once in the canary deployment model. In traditional roll out there is no limit on how many times you have to roll out the new version of your application.

The canary user: The canary user is a user that has access to your application but has a very limited instance of your application. In traditional roll out the same user has access to the same code, or at least to the same versions of the code.

The canary user is used to test new features without having to change anything else. The canary user can run your application in a way that will make it easy to see if something goes wrong.

What is canary deployment in Azure?

This post is an introduction to the canary deployment (or A/B testing) capability in Azure. We will see the different type of tests and how they work using some examples.

Canary Deployment. Let's say I have a website I am working on, and I would like to release it publicly. In order to test that my website works correctly (if there is anything wrong with it), I want to deploy a test version first so that I can collect all the feedback before making the final release. In Azure, this is what we call canary deployment.

When it comes to canary deployments, I have two choices. The canary release is done from the Azure portal, in which we use a simple template (that includes steps to automate it) to take care of uploading our changes to an Azure virtual machine (VMs), updating the website URL to point to the new VM and then updating it in the Azure portal to make it visible to the users. This kind of canary deployment is really simple and the only thing that needs to be manual is the update in the Azure portal.

The second kind of canary deployment is a manual operation (as opposed to the first one). That means we need to download a VM and upload the code changes to it. In this case, we can use a template to automate this process (using Azure Resource Manager templates). The main advantage here is that we have more control over what we are doing. We can also create more complex canary deployments, for example, if we want to A/B test our websites. I will show you how that can be done.

Azure A/B Testing. As mentioned above, the most common application for a canary deployment in Azure is to improve the quality of a website. The other way to look at it is as a way to make sure that the audience will respond well to the changes (a simple usability test, but more advanced tests are possible).

Another kind of use-case is to split your audience in 2 different versions of the website, each one getting a different experience. If your website has pages where you need a specific functionality (for example, a page where the users need to subscribe to a mailing list) you can split your audience in 2 versions: a version for users who need this kind of subscription functionality and the other one for those who do not.

What are the disadvantages of canary deployment?

There are a lot of downsides to using canaries: The system you use to monitor the canaries (puppet, chef, etc) only monitors your canary environment and has no visibility into other environments. When a canary stops working you can't tell which component (or if any component) is at fault without checking every other environment. You have no visibility into your environments except from the canary itself so when it breaks, you may never know why and what has caused it. As an alternative, you might want to look at things like AWS Cloudwatch Alarms and Amazon's SNS/Dynamo queue for notifications on your failures.

Why use canary deployment?

The benefits of using canary deployment with your cloud services is fairly simple: by setting up and maintaining a canary deployment, you can detect changes and ensure that any production problems can be detected and fixed before they are serious and cost you.

We will look at how to set up your own canary deployment in this blog post and explore the benefits of setting up a canary deployment using Circle CI. In order to build a canary deployment we first need to set up Circle CI to use the deploy keys that we've generated. Build your deployment key. To set up a canary deployment, you need to have a canary deployment key. These keys are created for use in CircleCI, and are not intended for production use (ie they can't be used on actual servers). The keys allow us to deploy to an environment without having to login to our Cloud Service which is particularly useful for testing out new features.

The keys are created in the following way: First you will need to generate a random password. You can do this easily enough with the random:true command line tool.

Once you've generated your password you will need to pass it to the add-key-to-user command line tool. This will create the deployment key pair in the current user account.

If you want to add this key to a different user account (for example a CircleCI service user) then you can use the add-key-to-user command line tool to do this.