Google has made the Java 8 runtime generally available on App Engine, the Google Cloud Platform’s development platform service. Google said the upgrade removes performance limitations Java developers have had to deal with when using the Java 7 runtime. Java 7 remains a supported option.
“Unfortunately, using Java 7 on App Engine standard environment also required compromises, including limited Java classes, unusual thread execution, and slower performance because of sandboxing overhead,” said Amir Rouzrokh, Google product manager.
These limitations are now removed with the move to Java 8. Google App Engine now offers an OpenJDK 8 JVM, the Jetty 9 web server and servlet container, the gRPC framework, and Google Cloud Client Library for Java. The standard App Engine environment also enables use of off-the-shelf frameworks such as Spring Boot and alternative JVM languages such as Kotlin. Support for Java 8 follows Google’s addition of support for C#, Node.js, and Ruby on App Engine in March.
Java 8 had been available on the App Engine standard environment in a beta release since earlier this quarter, with Google using the beta period to improve performance. With the general release, Java 8 is now covered by the App Engine Service Level Agreement, which features a 99.95 percent uptime clause. To migrate to Java 8, users add the java8 line to their appengine-web.xml file and redeploy the application.
The Java 8 JDK (Java Development Kit) was rolled out in March 2014. Oracle just last week introduced JDK 9, which introduces modularity and a host of other features. Rouzrokh notes that Google is “hard at work” to bring OpenJDK 9 support to App Engine.