On Wed, 28 Jan 2009 17:51:05 -0600, Tom Marchant <m42tom- [email protected]> wrote:
>On Wed, 28 Jan 2009 12:44:50 -0600, Arthur Gutowski wrote: > >>>On Fri, Jan 23, 2009 at 3:02 PM, Mark Zelden >>wrote: >> >>The book mentions the JES3 consideration for C/I, but unless I'm blind, it >>doesn't describe how to "refresh" the JES3 copy of the symbol table without >>IPL, namely *S <main>,CONNECT > >I'm confused, Art. I used SYMUPDTE many times when I was there and never >had any problems with JES3. Was there something that I was missing? Or was >I just lucky to have been wearing my bulletproof shoes that day? Ha! You probably were. Let me attempt, in my less-than-JES3-fluency try to address both Mark's and your questions. My original foray into this post is tangential, but I picked up on the reference to the IBM redbook, and thought someone might find useful some additional info on the JES3 caution useful. It's not that a program doesn't go through ASASYMBM service on a JES3 system, it's that JES3 C/I doesn't go through ASASYMBM for STC (including started JOBs) like JES2 does. ALIAS / SYMBOLICRELATE is unaffected because CATALOG uses ASASYMBM. Thus the tangent. On JES2, as with JES3, a batch job may go through C/I on one MAS member, but initiate on another - which is why you can't use system symbols in jobs. On JES2, STCs always C/I and execute on the same member where the START command were issued - which is why you can use system symbols in STCs. On JES3, that ain't necessarily so. I'm not sure if you *can* run multiple C/I's in a single JES3 MAS, but I know we don't. While we may be able to run C/I on a LOCAL, we always run it on the GLOBAL. This means an STC, unless started on the GLOBAL, will C/I on a different member than it executes. For JES3 to support symbols in STCs, the GLOBAL has to know the contents of all of it's LOCALs' symbol tables. To avoid overhead of obtaining the table, or parts of it, every time a START command is issued, JES3 obtains a copy of the symbol table for each member, including itself (to keep code path the same for each type of MAIN), only during CONNECT processing. CONNECT happens during initialization, but can be re-driven any time with a *S <main>,CONNECT. We never got burned during your tenure here because we hadn't yet tried to implement or back out a product involving a dynamic symbol change (to avoid IPL) that referenced said symbol in STC JCL. If you're curious, send me a note offline, and I'll cite examples and go into more (is that possible?) detail. HTH, Art Gutowski Ford Motor Company ---------------------------------------------------------------------- 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
