zOS Attachment Facilities: Pros and Cons

matt christensen · Posted: Thu Feb 28, 2008 6:28 am

Hello all, this is my first post and I'm very thankful for the existence of this forum.

I'm trying to gather some information about the main pros and cons of using TSO vs CAF in a batch environment.

I've found lots of "here's how you us CAF or TSO". But what I'm after is why one vs. the other, is there additional overhead, etc.

Can anyone point me to some data/research on this topic??

Thanks!

CICS Guy · Posted: Thu Feb 28, 2008 6:46 am

Just gotta do it....

Welcome to the forum, I'm sure that somebody that understands what you mean by CAF will be along shortly....

not d

matt christensen · Posted: Thu Feb 28, 2008 7:06 am

Perhaps I should elaborate on my question.

By attachment facility I mean:

The z/OS attachment facilities include:

CICS
IMS
TSO
CAF (call attachment facility)
RRS (Resource Recovery Services)

I'm trying to gather some thoughts on why, in a batch environment, one would use CAF vs. TSO.

CICS Guy · Posted: Thu Feb 28, 2008 7:14 am

matt christensen · Posted: Thu Feb 28, 2008 7:30 am

SUre, I'll try...I'm just getting acquainted myself.

In our shop there are some systems that have developed batch jobs that need DB2 data. These systems attach to DB2 in different ways. Some use TSO and some use CAF (call-attach).

Those that use TSO execute IKJEFT01 and specify a plan, load module, loadlib, etc. in the JCL. Executing IKJEFT01 creates the thread to DB2. So the load module can get DB2 data.

Those that use CAF pass some paramenters into an executable. The executatable calls a routine that creates the thread to DB2. It allows more control of the connection to DB2...I think.

Again, this is as I have come to understand in the last two days I've been reading/asking around.

There's some info http://publib.boulder.ibm.com/infocenter/dzichelp/v2r2/index.jsp?topic=/com.ibm.db29.doc.intro/db2z_db2attachmentfacilities.htm

but nothing about when to use which and why, etc.

Hope this helps and thanks for yours!!

Douglas Wilder · Posted: Thu Feb 28, 2008 9:26 pm

I have been told that CAF is more efficient than calling DB2 from TSO in a batch job.

Also note that "RRS z/OS Resource Recovery Services' is a newer implementation of CAF with additional capabilities." DB2 V.8

matt christensen · Posted: Fri Feb 29, 2008 11:54 pm

I've been told the same thing..but I'm looking for some 'proof' or documentation supporting that statement.