GETMAIN - Acquire storage from GDSA (above 2GB)

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

From the below link it seems that we can GETMAIN to acquire storage from GDSA:

publib.boulder.ibm.com/infocenter/cicsts/v3r2/index.jsp?topic=%2Fcom.ibm.cics.ts.performance.doc%2Ftopics%2Fdfht3_stats_stgmgr_0stat_above2GB.html

Not able to find the OPTIONs on GETMAIN command which will help in acquiring the storage from GDSA.

dbzTHEdinosauer · Posted: Wed Oct 12, 2011 1:45 pm

here is the link for GETMAIN Syntax

unless you specify the BELOW option, the memory will come from Above the 16Meg line.
which is what GDSA is.

Bill Woodger · Posted: Wed Oct 12, 2011 2:07 pm

Perhaps you just have to dig more for your answer.

If GETMAINs are possible above 2GB (since they are listed in the stats you point to) and you can find no new syntax for GETMAIN, perhaps it just means CICS satisfies your GETMAIN without you having to know where it is - as dbz says, if not below then it is above 16mb.

You'll probably have to keep digging to confirm this. If you feel the GETMAINs aren't going there because your system is still SOSing, then maybe you (or your technical staff) have to see if anything needs to be changed in the set-up to allow things to happen.

Have you tried listing the statistics from your system as the first obvious thing?

Do you have a little test CICS which you can risk blowing-up at some point without disturbing others? You could intersperse the GETMAINs and the stats and see if you can push the GETMAIN above into 2GB?

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

dbz,

get updated on the GETMAIN command:

publib.boulder.ibm.com/infocenter/cicsts/v4r2/index.jsp?topic=%2Fcom.ibm.cics.ts.performance.doc%2Ftopics%2Fdfht3_stats_stgmgr_0stat_above2GB.html

Current syntax does not allow to acquire storage above 2GB.

Hence i posted in this forum.

Bill,

Thanks for your advise.

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

Apologies,

exact link to get updated on GETMAIN

publib.boulder.ibm.com/infocenter/cicsts/v4r2/index.jsp?topic=%2Fcom.ibm.cics.ts.applicationprogramming.doc%2Fcommands%2Fdfhp4_getmain.html&resultof=%22%67%65%74%6d%61%69%6e%22%20

Bill Woodger · Posted: Wed Oct 12, 2011 2:44 pm

So you have a conundrum. The report shows no of GETMAIN/FREEMAIN above 2GB, yet you explicitly can't do GETMAIN/FREEMAIN above 2GB.

dbz can hardly be blamed for that, can he?

If you are seriously considering this for a necessary business task, do all the research you can, understand it all, and put in a call to "Hursley".

The usage shown for above 2GB that I found by traversing your links is not an everyday sort of thing. Until the use above 2GB is "transparent" to a CICS application programmer, I think you're probably on the wrong route.

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

Bill, yes its a conundrum.I will follow it up with IBM experts on CICS storage and update the oucome in this post.Was informing DBZ, that GETMAIN syntax doesn't support acquiring storage above 2GB.No intention of blaming.

dbzTHEdinosauer · Posted: Wed Oct 12, 2011 4:09 pm

yes,
as usual,
someone is a little thin skined about being called on their BS,

I never said above the 2gb line,
infact,
CICS has never really allocated above the 2 gb line,
only above and below the 16mg line.

but what are facts when we are really talking about face?

Garry Carroll · Posted: Wed Oct 12, 2011 5:09 pm

I seem to remember being told at Hursley that 'above the bar' storage is only available to Assembler at this time. Since most applications are developed using HLL, the CICS API does not support 'above the bar' storage. CICS itself, however, does exploit 'above the bar' storage so you do get stats on usage above 3Gb.

Garry.

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

Garry, Thanks for the information.

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

The BAR - 2 GB
The LINE - 16 MB

Above THE BAR is GDSA.Above THE LINE is not GDSA (as mentioned in replies to this post).

Bill O'Boyle · Posted: Wed Oct 12, 2011 5:34 pm

If a given program is COBOL, obtaining above-the-bar storage will not be addressable because COBOL hasn't been modified yet. However, the COBOL committee has plans to do so in the not to distant future.

I guess they had no other choice than to comply, as PL/I, C and Java are 64-Bit compliant (as well as Assembler) and with the billions of lines of COBOL executed daily (and not going away), it would only make sense.

But, acquiring 64-Bit storage in CICS was newly introduced with TS/4.2 as I don't recall it being available in TS/4.1 as well as any other TS Version/Release.

MEMLIMIT, for 64-Bit storage, was introduced with TS/3.2, mainly for CHANNEL and CONTAINER API usage above the bar, but not necessarily for 64-Bit data in a given program as not all languages have this addressability compliance, like COBOL.

Mr. Bill

Eshwar CICS · New User Joined: 18 May 2011 Posts: 47 Location: India

Truly amazing response Bill. I am finding it hard to integrate CHANNELS & CONTAINERS with the COBOL programs(when pushed to limits in terms of storage).CHANNELS & CONTAINERS can support huge data whereas to process that data we dont have proper storage mechanisms in Application programs.Again, many thanks for this wonderful response which gives a clear understanding of the limitation.