$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 ?

Algerian

Answer 1

No. Those messages are for jobs. Not all operations are jobs. An example of an operation that is not a job would be a system command. I don't have a z/OS system at hand right now, but I believe another example of an operation that would not use the messages you reference would be a started task.

This may be helpful, as it attempts to explain z/OS concepts in Unix terms.

Slipcase

Thanks for your reply. What is the difference between a job and an operation according to you ? – Algerian

A 'job' on the mainframe is a well-defined term and relates to running a program (or several programs) in batch mode, where you tell the system what you want to run and what datasets (files) you want the programs to use. You submit the job and the system runs it when it can and tells you when it has done so. An operation has no particular definition in mainframe terms, although several software products use the term (TWS - a scheduling package - to name but one). – Greysun

Answer 2

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. :-)

Greysun

Steve, when you say "the entire 4Gb range of memory", shouldn't that actually be 2Gb instead? If the code is AMODE 24, it can access 16M; if AMODE 31, then 2G; if AMODE 64, then 16 exabytes. – Wiseacre

Simon - you're right. I'll edit the answer to correct. Thanks. – Greysun

Answer 3

Work gets into z/OS through something called the subsystem interface. Part of this flow is that generally, when an address space is started, it requests work from the subsystem that started the address space through a well-defined interface (IEFSSREQ). This handshake is where things like your HASP messages come from.

Here's a watered down example.

An operator enters a START command from a system console. As part of processing that command, the system creates an address space, and eventually a thread in the new address space says, "ok - I'm ready...give me some work to do". This goes to the primary job entry subsystem, who hands the address space something to do - the internal data structures representing the task that the operator started in this case. As part of this chain, the various $HASP messages are issued, and this works pretty much the same way for TSO sessions, started tasks (STCs) and JCL submitted for a batch job.

JES2/JES3 are examples of subsystems, but there are others.

For example, if our operator added the SUB=MSTR parameter on the start command, the requests wouldn't go through the primary JES - and so there wouldn't be any of the $HASP messages you're looking for. There are plenty of vendor applications that start and manage address spaces outside of JES, and this is the stuff you miss by limiting yourself to the HASP and IEF401 messages.

Also, UNIX Services has a variety of APIs similar to UNIX "fork" that can be used to spawn address spaces without necessarily involving JES.

If you want to know about activity starting and ending, there are better ways - SMF, ENF signals, etc. A great way to learn this stuff if you don't know already is to use the system trace facilities and read some dumps. The wonderful thing about z/OS is that it's all right there, for those who spend the time figuring out where to look.

Prologue

Thanks for your help. It really helps. I'm actually working on a project related to IBM Mainframe. Would you mind contacting me via Email at [email protected] ? Thanks a lot in advance – Algerian

Answer 4

A job is something that goes through JES2/JES3. (In your case, JES2.) JES2/JES3 jobs are generally used for batch type of work. For example, a sort job, where I submit something, and come back later and get an answer. However, there's a lot of work running under z/OS that doesn't go through JES2/JES3.

Part of the problem here is what you mean by an operation; for example, while you may get a message saying that DB2 has started, after it's started, it's not going to tell you every time it gets a query. A TSO user might run a REXX exec underneath his/her address space, but that's not going to go through JES.

Another way to look at this is that JES2/JES3 are job management subsystems, but they aren't equivalent to the kernel on a unix/windows system, which does schedule all the work running on the system. For z/OS, there are multiple ways that work can come in to a system; examples include JES2/JES3, TSO, ISPF, CICS, DB2, IMS, via the console, etc. It's then up to the master scheduler/WLM/SRM to manage all the requests that come in through all of the subsystems.

If you have access to a z/OS system, look into SDSF, or whatever you use to manage JES2. The ST panel, under SDSF, is a list of things that are running/eligible to run that are managed by JES2. However, if you look at the DA panel (assuming you have authority to do so), you'll note that there are a lot of address spaces that show up on the DA panel that don't show up in the ST panel.

Daveta

Answer 5

If address spaces are started through the JES2-subsystem, which is normally the case unless another subsystem or MSTR is specified using the MVS START command, then the $HASP373 jobname STARTED is issued. Similarly, when the address space ends, message $HASP395 is issued.

The IEF403I and IEF404I messages are issued by the system in similar situations and independent of what either JES2 or JES3 are doing and regardless under what subsystem the address space was started. The messages are only issued when the operator has requested to monitor job names using the SETCON MONITOR or the MONITOR JOBNAMES command. Products for automated operations typically do this.

Braxton