- JZOS is actually part of the Java SDK for z/OS, not USS. - and to the OP's question: Java JVMs these days have "JIT" (Just in time) optimizing compilers that translate frequently used methods from byte codes into machine instructions. SDK 6 has a feature (AOT) whereby these optimizations can be reused over and over between different jobs.
For more information on JZOS: http://www-03.ibm.com/servers/eserver/zseries/software/java/jzos/overview.htm Kirk Wolf On Mon, May 5, 2008 at 2:12 PM, Clark F Morris <[EMAIL PROTECTED]> wrote: > On Fri, 02 May 2008 22:01:10 +0200, Thomas Zierer > <[EMAIL PROTECTED]> wrote: > > >JZOS has become part of Unix System Services in z/OS. Handling is very > >easy, especially if combined with other Java tools like ANT. There is an > >interesting sample shiped with JZOS: Installing an running a Apache > >Tomcat server as a batch job or started task. It really takes only a few > >minutes to get the server up and running. > > > >I havn't made any research on performance, but the last I've heard is > >that Java is about 30% slower as COBOL, which is reduced, if your S/390 > >uses special chips. Also IMS uses now special regions, JMPP and JBMP for > >Java apps but I'be have no experience with this. > > This gets complicated and speaks as much to IBM marketing as anything > else. Java batch may well take 30 to 50 percent more CPU yet cost > less because the Java is run on a zAAP which doesn't count toward > capacity when calculating software pricing. If someone got bright on > some of the Java functions, this may be even less. IBM pricing can be > a driving factor to moving to another language. What the marketing > droids fail to realize is that once all of an installations work load > is moved to C/C++, Java and the web, it becomes easy to move to > another platform. Of course it is harder to move to another language > than the enthusiasts of X claim. This is especially true if people > don't really know how the current system operates, down to the various > subtleties. I wonder if any organization knows even a good percentage > of their components and the implications of interaction. The number > of fixes needed for any of the operating systems of affliction or > choice from the various vendors leaves me skeptical. > > > >Regards > > > >Thomas > > > > > >Pakku schrieb: > >> I've spent much of this morning looking for some comparison between > >> the performance of Java and COBOL for batch programming on z/OS. I > >> haven't found any useful information and am hoping I might find some > >> here. > >> > >> I know that IBM bought the JZOS product a couple years back with the > >> intent of enabling Java in the batch world. > >> Has this taken off? > >> > >> Also read somewhere that given that Java has to be reinterpreted (from > >> the bytecode produced by compilation) by the JVM at runtime, there is > >> no way it could outperform COBOL in classical batch processes like > >> payroll or month-end credit card statement processing. > >> > >> Is this so? > >> > >> Would really appreciate hearing from anyone who has experience with > >> JZOS or other forms of running batch Java on MVS. > >> > >> Thanks! > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
