According to Brett Slatkin of Google's App Engine Team, a new a billing feature for App Engine is on the horizon, which will enable an app to grow beyond Google's free quotas. He also unveiled an App Engine System Status Site that monitors the latency and uptime of various components and provides real-time visibility into their performance, and a new Quota Details Dashboard.

The new System Status Site, Slatkin explains, provides a detailed view into the performance of various App Engine components using some of the same raw monitoring data that our engineering team uses internally. This includes:

• up-to-the-minute overview of our system status with real-time, unedited data
• daily overall serving status for each of our APIs, including any outages or downtime
• detailed historical latency and error-rate graphs for the App Engine Datastore, Images, Mail, Memcache, Serving, URL Fetch, and Users components

Slatkin adds:

"In addition to the Downtime Notify Google Group, we'll use this dashboard to announce scheduled downtime and explain any issues that affect App Engine applications. You'll be able to see real data behind any issues that we experience along with explanations from our team.

We'll continue to tune this dashboard to make sure we're providing useful and accurate information about App Engine's uptime. We expect this tool will complement others offered by other companies, such as Hyperic's CloudStatus."

He then goes on to detail the other seasonal gifts from Google, as follows:

"Quota Details Dashboard

For each App Engine application, we now provide a Quota Details Dashboard. This makes it easier to track how much of the free quota your app is using up across bandwidth, CPU, etc. Use it to get detailed information about all of the resource quotas that affect your application.

To use the Quota Details Dashboard, click the "Quota Details" link on the dashboard for any app.

Sneak Preview: Purchasing Additional Resources

As mentioned in the product roadmap, soon you'll be able to buy additional capacity beyond the free quotas. (For reference, we described our expected pricing earlier.) In the mean time, we wanted to give you a brief update on this feature.

You'll be able to buy capacity based on a daily budget for your app, similar to the way AdWords spending works. You'll have fine-grained control over this daily budget so you can apply it across CPU, network bandwidth, disk storage, and email as you see fit. You'll only pay for the resources your app actually uses, not to exceed the budget you set. Here are a couple screenshots from the beta interface:

Of course, we're still working on this feature, so we'll likely make additional changes before releasing it."