Auto scaling rules as specified executes based on the following rules:
- Constraint Rule: Constraint rules consists of one or more actions to set minimum and maximum values for the number of instances of a target, a rank, and optionally a timetable that defines when the rule is in effect. If there is no timetable, the rule is always in effect.
- Reactive Rule: This rule is based on varied metrics or constraints.
- Remember, constraint rules always take precedence over reactive rules, to ensure that these reactive rules cannot continue to add new role instances above a maximum value or remove role instances below a minimum level.
Now, let's check on the latest on auto scaling improvements integrated from Azure Management Portal. First , let's create a new cloud service and deploy the ASP.NET web role package.
- Specify the settings for the role, add custom diagnostic plans from settings (support from Azure SDK 2.0) configured with your storage account.
- Let's publish the cloud service and start monitoring the configuration dashboard.
- Let's open the scale tab from the Cloud service details pane. Check the scaling settings by schedule , setting by metric (none, CPU, queue length).
- Let's set up the schedule time span for adding / removing role instance settings.
- Specify the setting rules for autoscaling metrics; in this demo , I have set up schedule rules for daytime of our cloud service.
- You can configure the notification alerts from Azure Management Portal itself using the "Management Service" tab.
- To create a notification alert for autoscale, click the Add Rule icon and specify the rule settings.
- After creating the rule , check the dashboard of rule alert to monitor the activated notifications.
- From the latest add-ons of auto scaling improvements in hosted services, an updated preview of web endpoints is also available. Click on the Web endpoint preview section of your cloud service. For this demo, I have configured two web endpoints for monitoring the scale metric and logging the throttling information (minimal) in the selected storage. Similarly, an option of Linked Resource (SQL database, Storage Account) is also available now from the Azure Management portal itself.