IBM Mainframe Forum

Performance improvement is based upon the idea that a computer program either runs I/O-bound (waiting for I/O to complete), or CPU-bound (waiting for CPU time to complete). A CPU-bound program can have I/O reduced almost to nothing and the elapsed time changes little, if any, as the I/O is not the bottleneck. An I/O-bound program can be reduced to almost no CPU time without changing the elapsed time. If the program is CPU-bound, you improve performance by making code changes because the code is almost always what is taking the time -- tables and data base access are often causative agents for CPU consumption. If the program is I/O-bound, you improve performance by making changes to reduce I/O -- increasing buffers (30 to 50 per sequential file, appropriate numbers for other file types), moving tape processing to disk, using cache to replace disk access.

If you do not know whether the program is I/O-bound or CPU-bound, all you can do is guess when attempting to improve its performance. Start by adding buffers and making other I/O changes -- if there is no significant change, then assume you're going to have to dig into the code to figure out where the program is spending the most time. If you can shift the program run time to an less busy part of the day, that may be a major improvement.

However, first you must determine what is acceptable run time. This can vary by site and sometimes even by application. You cannot expect a program to be able to read 25,000,000 records, for example, in 2 minutes -- but neither should it take 13 hours (although I have worked on systems where that was true).

dick scherrer wrote:Hello,

When i looked at this earlier, there was one or two attachments. Unless i am mistaken. At any rate, there are none now. . . Which is probably just as well. I suspect your client would not want their code posted on the internet. . .

You gave replay can't reduce I/O.

This is not what i replied. . . What i said was that increasing the buffers might improve the elapsed time, but won't change the i/o count - not at all what you posted. I suspect that much of the difficulty with this situation is communication.

I am not sure there even is a problem. . . If the client has incorrect documentation and code they cannot understand, it may be a long summer. Is there any correspondence to/from the client that explains what they really want done? If ther is not, i suggest some be created. If everyone involved does oot know the goal, it is very difficult to reach.

Hi Duck,

I removed my attachments,not my client ,Now Again I attached here, once you download, please give reply, I will remove...
Now again I added here my source. old existing NRAM6905.txt(COBBAT),
In my style reading seq using evaluate.... logic ... RMTYB005.txt(COBBAT).

Can you understand my post or not?
Just My client was said performance for this program and job.

In my client performance means they required new coding same existing logic. But easy to understandable.
my client requires - easy understandable code and they need program specifications , flow.

so, here I am doing reverse coding means if ..Then else instead of i am using evaluate...

Please advice for Coding technical specification on COBOL Language & do you have any tools if you gave source and convert flow diagrams & specifications. if any of these related information document's please pass to me.

"I am not sure there even is a problem. . . If the client has incorrect documentation and code they cannot understand, it may be a long summer. Is there any correspondence to/from the client that explains what they really want done? If ther is not, i suggest some be created. If everyone involved does oot know the goal, it is very difficult to reach"

My client just gave to me job name and tell documentations work.
once I completed and passed to my client.
again this time asked client do performance improve.
this time i didn't understand what they mean performance....
I checked all input, output file record count and execution time , its works good.
just last day I asked again to my client,
this time only my client says. "you do new code and gave new documents and flow digrams for this job and program"

that's reason i am asking to you, provide any technical documents & flow digrams to me...

Thank you,
Regards,
Ram T

Hello,

As i mentioned before - the main problem with this is communication. I beleive there is a communiation breakdown between you and the client and there is a breakdown between you and us (here at the forum). For example:

that's reason i am asking to you, provide any technical documents & flow digrams to me...

How could we possibly provide anything related to this? 100% of whatever material exists is on that system or in documentation there. We/i have zero related documents or flow diagrams. We can't have as we have no knowledge of that system/application.

Suggest "renting" a local senior to provide assistance would possibly help. . .

Hi Duck,

Thank you very much,
My client also not provideing any document's to me.
Just they pass job name only.
my client don't have document's,

I understand what is problem,what I need to do,But I am expecting more related docs for performance issue - how to check? What is the procedure? becasue this is my first issue on performance issue side.

just "Visustin v6.0 Demo"(check this site:www.aivosto.com) this software if any old code give and click convert flow digram then it will convert. This software only 30 days trail version with me,But can't save and print for flow, just view only.
this software.. like you have any tools or realted documents in general, I am asked to you, pass to me.

ok, any way thanks very much.

Thank you,
Regards,
Ram T