The JVM is Java's solution for application portability across different platforms, but Docker can offer an effective complement, stressed Al Tobey, open source mechanic at Datastax. "It provides a bunch of stuff that the JVM doesn't do," Tobey said following his presentation on Docker at a Silicon Valley Java User Group meeting this week. "The JVM has really good sandboxing. It's very well-respected, it has pretty good memory control. What it doesn't have is really sophisticated CPU resource control, and so Docker brings that to the table. It also brings the packaging of the entire JVM with the JARs and all the different parts of the app into one container."