How to: Retain a Constant Virtual IP Address for a Cloud Service
Updated: November 21, 2014
When you update a cloud service that's hosted in Azure, you might need to ensure that the virtual IP address (VIP) of the service doesn't change. Many domain management services use the Domain Name System (DNS) A record method for registering domain names, which works only if the VIP remains the same. You can use the Publish Wizard in Azure Tools to ensure that the VIP of your cloud service doesn’t change when you update it. For more information about how to use DNS domain management for cloud services, see How to Configure a Custom Domain for an Azure Cloud Service.
The VIP of a cloud service is allocated when you first deploy it to Azure in a particular environment, such as the Production environment. The VIP doesn’t change unless you delete the deployment explicitly or it is implicitly deleted by the deployment update process. To retain the VIP, you must not delete your deployment, and you must also make sure that Visual Studio doesn’t delete your deployment automatically. You can control the behavior by specifying deployment settings in the Publish Wizard, which supports several deployment options. You can specify a fresh deployment or an update deployment, which can be incremental or simultaneous, and both kinds of update deployments retain the VIP. For definitions of these different types of deployment, see Publish Azure Application Wizard. In addition, you can control whether the previous deployment of a cloud service is deleted if an error occurs. The VIP might unexpectedly change if you don't set that option correctly.
After you’ve deployed your cloud service at least once, open the shortcut menu for the node for your Azure project, and then choose Publish.
The Publish Azure Application wizard appears.
In the list of subscriptions, choose the one to which you want to deploy, and then choose the Next button.
The Settings page of the wizard appears.
On the Common Settings tab, verify that the name of the cloud service to which you’re deploying, the Environment, the Build Configuration, and the Service Configuration are all correct.
On the Advanced Settings tab, verify that the storage account and the deployment label are correct, that the Delete deployment on failure check box is cleared, and that the Deployment update check box is selected.
By selecting the Deployment update check box, you ensure that your deployment won't be deleted and your VIP won't be lost when you republish your application. By clearing the Delete deployment on failure check box, you ensure that your VIP won't be lost if an error occurs during deployment.
To further specify how you want the roles to be updated, choose the Settings link next to the Deployment update box, and then choose either the incremental update or simultaneous update option in the Deployment update settings dialog box.
If you choose incremental update, each instance is updated one after another, so that the application is always available. If you choose simultaneous update, all instances are updated at the same time. Simultaneous updating is faster, but your service might not be available during the update process.
When you’re satisfied with your settings, choose the Next button.
On the Summary page of the wizard, verify your settings, and then choose the Publish button.
|If the deployment fails, you should address why it failed and redeploy promptly, to avoid leaving your cloud service in a corrupted state.|