$HASP373 and IEF403I z/os syslog

Question

I ask myself a question about the z/os log:

I just would like to know if all the operations getting started were always called by $HASP373 and IEF403I ? And for the status Ended called by $HASP395 and IEF404I ?

Answer 1

The trouble with z/OS is that it's really hard to explain something without introducing another concept that also needs explaining. This, in turn, requires another explanation etc. This is partly due to the z/OS operating system being from a different planet compared to Unix, Windows, OS X etc, all of which are broadly similar.

Those messages are issued by the system for a lot of the work that happens on a mainframe, but not all of it.

All work on z/OS runs in its own address space, which is almost like a mini-VM. There will be many address spaces in a z/OS system (380 in ours currently). A program in an address space is not aware of any other address spaces and thinks it has access to the entire 2Gb (31-bit addressing) range of memory (different address spaces can communicate if necessary & authorised, and more than 2GB is available with 64-bit addressing). A program in one address space cannot crash a program in another address space by overwriting storage. Programs in 2 different address spaces can access the same memory address, but don't affect each other, as they will actually, unbeknown to them, access different memory.

There are 4 types of address spaces:

• TSO (Time Sharing Option) - these are users logged on to the system, typing commands and getting responses. They may run scripts, using the languages REXX and Clist (Command Lists - older, generally replaced by REXX) much like Perl and shell scripts, submit batch jobs, write and compile code etc.
• BATCH JOBS (or JOB) - This is where you want to run a program, so you create a text file with the name of the program(s) to run and the file(s) that it/they need(s) and SUBMIT it. The system will run the program(s) and tell you when they are done, Whilst running, you can go and do something else. You don't even need to be logged on - you can prepare an FTP job (for example) to run at 01:00 whilst you're asleep and another job to run if the first one works.

• STARTED TASKS (STCs) - Very similar to a batch job. Usually started either by the system itself when it starts or by an operator issuing a START command for that STC at the system console. (E.g. 'START DB2' starts the DB2 started task. Alternatively a user may submit a batch job for their own test DB2 system.)

• System Address Spaces (SYSAS). Consider these like a Unix daemon. started by the operating system itself for various essential processes. There are also address spaces representing processes running under the 'Unix' half of z/OS (USS - Uxniz System Services), but that's another story.

There is no such thing as an 'operation' in z/OS terms. Within an address space, many programs may be running, each one identified by a TCB (Task Control Block) or SRB (System Request Block).

However, if you knew that the information you wanted was produced by a normal batch job, then looking for the £HASP373 and £HASP395 messages for that job would be the right place to start. Bear in mind that the message ids (HASP373 and HASP395) might not start with a '£' on your system. '£' is the default, but it is a customisable parameter. $ and # are also fairly common.

I do know what I'm talking about, but if any of the above is not clear, then I haven't explained it very well. I may be guilty of doing exactly what I warned against and explaining an unknown concept by using another unknown concept. :-)