Google AppEngine

queue.add(     DatastoreServiceFactory.getDatastoreService().getCurrentTransaction(),     TaskOptions.Builder.url("/path/to/my/worker"));

Please support the ability to server static files from the runtime based on regex patterns similar to the current Python runtime. Currently the only way to simulate this functionality is with a servlet. This is not ideal peformance, as evidenced by existing special handling of static files. The most compelling use case is for versioning static files with the app's version ID so that browsers can maximally cache static files without experiencing stale caches later when the app is updated.

Once you've enabled OpenID authentication for your app, a few things change: URLs generated by create_login_url without a federated_identity parameter specified will redirect to the OpenID login page for Google Accounts. URLs that are protected by "login: required" in app.yaml or web.xml will result in a redirect to the path "/_ah/login_required", with a "continue" parameter of the page originally fetched. This allows you to provide your own openid login page. URLs generated by create_login_url with a federated_identity provider will redirect to the specified provider.

many users, when asked for their "openid URL" will simply look at you in puzzlement. What we need is a solution that avoids the need for most users to enter their URL themselves, while still allowing savvy users to do just that. Fortunately, there are a number of such solutions. One of them is clickpass. After signing in there and setting up an entry for your site, they'll provide you with code for a button that you can embed in your login page, and which allows users to choose from a number of well-known identity providers, including Hotmail, Yahoo!, Google, and Facebook, as well as entering their own URL.

Originally my application started out using Spring MVC and JDO. The first use of JDO took my application about 5 seconds to get everything set up.  Similarily, Spring MVC added around 6 seconds to the cold start  time

 If you are not using either JDO or JPA, you can safely delete all related libraries (ones that have JDO, JPA, or Datanucleus in their name) and use the command line tool to upload your app. Deleting these libraries shaves about 400ms off of cold start time.

An Entity is an individual record that gets stored and retrieved from the datastore. The Kind is the unique string identifier of the type of entity. For example, "Joe" is an Entity with age=42, dob=10-12-2000, and Kind "Person".

Cold-start latency is determined by the time it takes to load all the classes needed to handle the request. If you upload a JAR file, but nothing references it, it won't be loaded, and thus won't affect your cold-start latency.

Only those jars under WEB-INF/lib will be uploaded to GAE. You can prevent GWT jars from being uploaded by not placing them under WEB-INF/lib, rather by externally linking to them in your project build path.

There's a 30 second deadline for web requests, and a 10 second deadline for URLFetch requests. You'll want to make sure you aren't exceeding either of these.

You must have two things in consideration: the appid and version must match, and you should enable datastore writes.

Well java.lang.System is whitelisted, so won't java.lang.System.out.println(...) work?