IBM Releases New 64-bit Java SDK for z/OS
IBM has updated the Java virtual machines and software development kits for its System z mainframe line to take advantage of new instructions in the zEnterprise 196 mainframes it began shipping last September.
In its announcement letter IBM says it has completely re-engineered the JDK, and the IBM Just-In-Time (JIT) compiler, whilst maintaining compliance with the Java SDK 6 compatibility test.
The mainframe JVM, based on version 2.6 of IBM's J9 virtual machine, includes security features for Java applications that are unique to the mainframe JVM, such as support for AES secure keys in the cryptographic co-processors. The updated JDK also includes updates to the JZOS batch toolkit, which allows Java applications to be submitted in batch mode to the mainframe engines.
There are two JDKs available. One is a 31-bit version that runs in System/370-XA mode to support older applications, the other a 64-bit version that can run in System z mode. The JDKs require z/OS v1.10 or higher. As well as the zEnterprise 196 machines the JDKs will run on the System z10 Enterprise Class (EC) high-end and Business Class (BC) midrange mainframes. They are also supported on a number of older machines which are no longer sold by IBM, including the z9 EC and BC mainframes, the z800 and z890 midrange boxes, and z900 and z990 high-end machines.
The zEnterprise 196 mainframe is based on a z196 microprocessor, which is a 5.2 GHz quad-core out-of-order CISC-based z/Architecture processor. The machine can have a maximum of 24 processors giving a total of 96 cores, 80 of which will be available to run the operating systems. The zEnterprise 196 allows up to 3 TB of RAIM (Redundant Array of Independent Memory).
Whilst it is probably the case that the majority of Java applications are run on x86 based systems, mainframes are still heavily used in large banking, insurance and manufacturing companies. IBM doesn't break out the sales of the new machines directly, but judging by IBM's fourth quarter results they look to have been impressive. IBM's revenues rose 7 per cent, to $29bn, and net income rose by 9 per cent, to $5.3bn, in the quarter after it began shipping the new machines. System z mainframe revenue was up 69 percent.
Dmytro Svarytsevych Oct 30, 2014