With 01/16/2014 release, AzureWebsites now support AlwaysOn. AlwaysOn feature when enabled on a site, will automatically ping the site at regular intervals to ensure that the AzureWebsite is always up and running, so that app domain or worker process will not be killed due to idleness. In reality, Azure runtime removes idle sites from memory, With new release we can prevent idleness by enabling AlwaysOn.
This new feature is only available to Standard mode websites. Hope Azure team will extend this feature to free and shared modes Websites too. As an alternative for free/shared mode websites, we have one more new feature called Web Jobs which can be use to run scheduled jobs. One more option is to use Azure Scheduler Service to ping sites on particular interval.
The big question to be answered by Azure team is – “As a matter of fact, Reserved(Standard) instances are always (even prior to this release) highly available (reference1, reference2), then why this AlwaysOn feature is considered as NEW FEATURE for standard mode websites? Is it now simply a turn on/off option available on management portal UI, isn’t it? I see only a turn OFF feature to be new. I also do suggest Azure team, to remove this option from Configure tab and include it in Web Jobs tab itself. That will give good amount of clarity for end users on customizing the time required for scheduling the requests.”
AlwaysOn for a particular AzureWebsite can be configured at Configure tab of the site in Azure Management portal.
Hope this new AlwaysOn feature is useful to many of you. Happy coding!!!