App Engine 1.5.0 Release

The App Engine team has been working furiously in preparation for Google I/O time and today, we are excited to announce the release of App Engine 1.5.0, complete with a bunch of new features. This release brings a whole new dimension to App Engine Applications with the introduction of Backends, some big improvements to Task Queues, a completely new, experimental runtime for the Go language, High Replication Datastore as the new default configuration (and a lower price!), and even more tweaks and bug fixes.

Serving Changes

• Backends: Until now all App Engine applications have been running on short-lived dynamic instances that we spin up and down in response to application requests. This is great for building scalable web applications, but has a number of limitations if you are looking to build larger, long-lived, and/or memory intensive infrastructure. With 1.5.0, we are introducing Backends which will allow developers to do precisely this! Backends are developer-controlled, long-running, addressable sets of instances which are as large as the developer specifies. There are no request deadlines, they can be started and stopped (or dynamically start when called), they can use between 128M and 1G of memory and proportional CPU. If you’d like to find out more, have a read through our Backend docs for Java and Python.
• Pull Queues: Most of our users are heavily using Task Queues in their applications today, but there is lots of room for more flexibility. With 1.5.0 we are introducing Pull Queues to allow developers to “pull” tasks from a queue as applications are ready to process them, rather than relying on Task Queues to push tasks at a pre-configured rate. This means you can write a Backend to do some background processing and pull 1, 10, or 100s of tasks off the Pull Queue when the Backend is ready for more. In addition, we’ve introduced a REST API which will allow external services to do the same thing. For example, if you have an external server running to do image conversion or OCR, you can now use the REST API to pull tasks off, run them, and return the results. In conjunction with these 2 improvements, we’ve also increased the payload limits and processing rate. We are excited both about expanding the use of Task Queues as well as improving the ease of integration between App Engine and the rest of the cloud.

Datastore

• High Replication Datastore as default: After months of usage and feedback on the High Replication datastore (as well as a record of 99.999% uptime so far) we are now confident that it is the right path forward for the majority of our users. So, today we are doing two things: setting HRD as the default for all new apps created, lowering the price of HRD storage from $0.45 down to $0.24, and encouraging everybody to begin plans to migrate. We really appreciate all the time that early users of HRD put into trying it out and finding issues and have fixed a number of those issues with this release.

Changed APIs

• In response to popular demand, the HTTP request and response sizes have been increased to 32 MB.
• Mail API: We have added a few restrictions to the Mail API to improve the reliability and reputation of the service for all applications. First, emails must be sent from email accounts managed by Google (either Gmail, or a domain signed up for Google Apps). Second, we’ve reduced the number of free recipients per day from 2000 to 100 for newly created applications. Both of these will help ensure mail from your application arrives at the destination reliably.

Administration

• Code downloads: As of 1.5.0, we have expanded the ability to download an Application’s source code to include both the user who uploaded the code to download it as well as the Owner(s) of the project as listed in the Admin Console. Owners were introduced in 1.4.2 as an admin role.

Go

• New runtime: With 1.5.0 we are launching an experimental runtime for the Go Programming Language. Go is an open source, statically typed, compiled language with a dynamic and lightweight feel. It’s also an interesting new option for App Engine because Go apps will be compiled to native code, making Go a good choice for more CPU-intensive tasks. As of today, the App Engine SDK for Go is available for download, and we will soon enable deployment of Go apps into the App Engine infrastructure. If you’re interested in starting early, sign up to be first through the door when we open it up to early testers. See the announcement on the Go Blog for more details.

There are plenty of additional changes and bug fixes in this release so please check out the full release notes, including all issues fixed for Java and Python. Finally if you are interested in where App Engine is heading later this year, check out our other announcement at I/O 2011!

The App Engine Team