Page History

...

JEP 229 may affect code that uses keystores. It changes the default keystore type from JKS to PKCS12. By default, new keystores will be created in the PKCS12 keystore format. Existing keystores will not change and keystore applications can continue to explicitly specify the keystore type they require. 

Make G1 the Default Garbage Collector

JEP 248 may affect code that does not explicitly specify the Garbage Collector to use. It makes the low-pause collector G1 the default garbage collector on 32- and 64-bit server configurations.The resource usage of G1 is different from Parallel GC, which is currently the default.

When resource usage overhead needs to be minimized a collector other than G1 should be used, and after this change the alternate collector will have to be specified explicitly.

Modular Run-Time Images

JEP 220 may affect code that relies on the removed endorsed-standards override mechanism, the removed extension mechanism, and the existence of rt.jar and tools.jar files as well as the old directory layout of files in the JDK & JRE installation image.

...

Feedback on new JDK 9 features

Make G1 the Default Garbage Collector

As described in JEP 248, switching to a low-pause collector in JDK 9 such as G1 should provide a better overall experience, for most users, than a throughput-oriented collector such as the Parallel GC, which is currently the default. A call for feedback and data points regarding this change went out on the hotspot-dev mailing list, where such input should be provided.

...